feat(headless): hydrate isolated collision worlds

src/AcDream.App/Input/LocalPlayerRuntimeState.cs

@@ -69,28 +69,6 @@ internal sealed class LocalPlayerModeState : ILocalPlayerModeSource
     }
 }
 
-/// <summary>
-/// Session-scoped server-authoritative movement skills. Player-description
-/// delivery and player-mode construction share this owner so rebuilding the
-/// local physics controller cannot fall back to stale defaults.
-/// </summary>
-internal static class LocalPlayerSkillProjection
-{
-    public static bool ApplyTo(
-        AcDream.Runtime.Gameplay.RuntimeMovementSkillState skills,
-        PlayerMovementController? controller)
-    {
-        ArgumentNullException.ThrowIfNull(skills);
-        AcDream.Runtime.Gameplay.RuntimeMovementSkillSnapshot snapshot =
-            skills.Snapshot;
-        if (controller is null || !snapshot.IsComplete)
-            return false;
-
-        controller.SetCharacterSkills(snapshot.RunSkill, snapshot.JumpSkill);
-        return true;
-    }
-}
-
 internal interface IViewportAspectSource
 {
     float Aspect { get; }

src/AcDream.App/Input/PlayerModeController.cs

@@ -361,7 +361,9 @@ internal sealed class PlayerModeController :
                 exactMovement.CancelMoveTo(WeenieError.ActionCancelled);
             };
 
-            if (LocalPlayerSkillProjection.ApplyTo(_skills, controller))
+            if (RuntimeMovementSkillProjection.ApplyTo(
+                    _skills,
+                    controller))
             {
                 Console.WriteLine(
                     $"live: {loggingTag} — applied server skills "

src/AcDream.App/Net/LiveSessionRuntimeFactory.cs

@@ -277,7 +277,7 @@ internal sealed class LiveSessionRuntimeFactory
             ResolveSkillFormulaBonus: skillCreditResolver.Resolve,
             OnSkillsUpdated: (runSkill, jumpSkill) =>
             {
-                if (LocalPlayerSkillProjection.ApplyTo(
+                if (RuntimeMovementSkillProjection.ApplyTo(
                         _domain.Character.MovementSkills,
                         _player.Controller.Controller))
                 {

src/AcDream.App/Streaming/LandblockBuildFactory.cs

@@ -164,11 +164,19 @@ public sealed class LandblockBuildFactory
 
         // Task 8: merge stabs + scenery + interior into one entity list.
         var merged = new List<AcDream.Core.World.WorldEntity>(hydrated);
-        merged.AddRange(BuildSceneryEntitiesForStreaming(
+        merged.AddRange(
-            baseLoaded,
+            _dumpSceneryZ
-            lbX,
+                ? BuildSceneryEntitiesForStreaming(
-            lbY,
+                    baseLoaded,
-            request.Origin));
+                    lbX,
+                    lbY,
+                    request.Origin)
+                : LandblockPhysicsContentBuilder
+                    .HydrateProceduralScenery(
+                        _dats,
+                        baseLoaded,
+                        worldOffset,
+                        _heightTable));
         var envCellBuild = new AcDream.App.Rendering.Wb.EnvCellLandblockBuildBuilder(landblockId);
         merged.AddRange(BuildInteriorEntitiesForStreaming(
             landblockId,

src/AcDream.Content/LandblockPhysicsContentBuilder.cs

@@ -4,6 +4,7 @@ using AcDream.Core.Meshing;
 using AcDream.Core.Physics;
 using AcDream.Core.World;
 using DatReaderWriter.DBObjs;
+using DatReaderWriter.Types;
 using DatEnvironment = DatReaderWriter.DBObjs.Environment;
 
 namespace AcDream.Content;
@@ -16,10 +17,16 @@ namespace AcDream.Content;
 /// </summary>
 public static class LandblockPhysicsContentBuilder
 {
+    public readonly record struct StaticCollisionPublication(
+        int BspOwnerCount,
+        int SetupOwnerCount,
+        int NoCollisionCount);
+
     public static IReadOnlyList<WorldEntity> HydrateStaticEntities(
         IDatReaderWriter dats,
         LoadedLandblock source,
-        Vector3 worldOffset)
+        Vector3 worldOffset,
+        bool includeVisualBounds = true)
     {
         ArgumentNullException.ThrowIfNull(dats);
         ArgumentNullException.ThrowIfNull(source);
@@ -35,13 +42,12 @@ public static class LandblockPhysicsContentBuilder
                 GfxObj? gfx = dats.Get<GfxObj>(sourceId);
                 if (gfx is not null)
                 {
-                    (Vector3 Min, Vector3 Max)? partBounds =
+                    if (includeVisualBounds
-                        GfxObjBounds.Get(gfx);
+                        && GfxObjBounds.Get(gfx) is { } partBounds)
-                    if (partBounds is not null)
                     {
                         bounds.Add(
                             Matrix4x4.Identity,
-                            partBounds.Value);
+                            partBounds);
                     }
                     meshRefs.Add(new MeshRef(
                         sourceId,
@@ -59,13 +65,12 @@ public static class LandblockPhysicsContentBuilder
                             dats.Get<GfxObj>(meshRef.GfxObjId);
                         if (gfx is null)
                             continue;
-                        (Vector3 Min, Vector3 Max)? partBounds =
+                        if (includeVisualBounds
-                            GfxObjBounds.Get(gfx);
+                            && GfxObjBounds.Get(gfx) is { } partBounds)
-                        if (partBounds is not null)
                         {
                             bounds.Add(
                                 meshRef.PartTransform,
-                                partBounds.Value);
+                                partBounds);
                         }
                         meshRefs.Add(meshRef);
                     }
@@ -94,6 +99,151 @@ public static class LandblockPhysicsContentBuilder
         return hydrated;
     }
 
+    /// <summary>
+    /// Hydrates retail's deterministic Region/Scene-generated outdoor
+    /// scenery into the same immutable entity shape consumed by graphical
+    /// and direct hosts. The supplied offset is the host's current
+    /// landblock-relative world origin; DAT placement remains local.
+    /// </summary>
+    public static IReadOnlyList<WorldEntity> HydrateProceduralScenery(
+        IDatReaderWriter dats,
+        LoadedLandblock source,
+        Vector3 worldOffset,
+        ReadOnlySpan<float> heightTable,
+        bool includeVisualBounds = true)
+    {
+        ArgumentNullException.ThrowIfNull(dats);
+        ArgumentNullException.ThrowIfNull(source);
+        if (heightTable.Length < 256)
+        {
+            throw new ArgumentException(
+                "The retail terrain height table must contain at least 256 entries.",
+                nameof(heightTable));
+        }
+
+        Region? region = dats.Get<Region>(0x13000000u);
+        if (region is null)
+            return [];
+
+        HashSet<int>? buildingCells = null;
+        LandBlockInfo? info = dats.Get<LandBlockInfo>(
+            (source.LandblockId & 0xFFFF0000u) | 0xFFFEu);
+        if (info is not null)
+        {
+            buildingCells = [];
+            foreach (BuildingInfo building in info.Buildings)
+            {
+                int cellX = Math.Clamp(
+                    (int)(building.Frame.Origin.X / 24f),
+                    0,
+                    8);
+                int cellY = Math.Clamp(
+                    (int)(building.Frame.Origin.Y / 24f),
+                    0,
+                    8);
+                buildingCells.Add(cellX * 9 + cellY);
+            }
+        }
+
+        IReadOnlyList<SceneryGenerator.ScenerySpawn> spawns =
+            SceneryGenerator.Generate(
+                dats,
+                region,
+                source.Heightmap,
+                source.LandblockId,
+                buildingCells);
+        if (spawns.Count == 0)
+            return [];
+
+        var entities = new List<WorldEntity>(spawns.Count);
+        uint landblockX =
+            (source.LandblockId >> 24) & 0xFFu;
+        uint landblockY =
+            (source.LandblockId >> 16) & 0xFFu;
+        uint sceneryCounter = 0u;
+        foreach (SceneryGenerator.ScenerySpawn spawn in spawns)
+        {
+            var meshRefs = new List<MeshRef>();
+            var bounds = new LocalBoundsAccumulator();
+            Matrix4x4 scale =
+                Matrix4x4.CreateScale(spawn.Scale);
+            if ((spawn.ObjectId & 0xFF000000u) == 0x01000000u)
+            {
+                GfxObj? gfx = dats.Get<GfxObj>(spawn.ObjectId);
+                if (gfx is not null)
+                {
+                    if (includeVisualBounds
+                        && GfxObjBounds.Get(gfx) is { } partBounds)
+                    {
+                        bounds.Add(scale, partBounds);
+                    }
+                    meshRefs.Add(new MeshRef(spawn.ObjectId, scale));
+                }
+            }
+            else if ((spawn.ObjectId & 0xFF000000u) == 0x02000000u)
+            {
+                Setup? setup = dats.Get<Setup>(spawn.ObjectId);
+                if (setup is not null)
+                {
+                    foreach (MeshRef meshRef in SetupMesh.Flatten(setup))
+                    {
+                        GfxObj? gfx =
+                            dats.Get<GfxObj>(meshRef.GfxObjId);
+                        if (gfx is null)
+                            continue;
+                        Matrix4x4 partTransform =
+                            meshRef.PartTransform * scale;
+                        if (includeVisualBounds
+                            && GfxObjBounds.Get(gfx) is { } partBounds)
+                        {
+                            bounds.Add(partTransform, partBounds);
+                        }
+                        meshRefs.Add(new MeshRef(
+                            meshRef.GfxObjId,
+                            partTransform));
+                    }
+                }
+            }
+            if (meshRefs.Count == 0)
+                continue;
+
+            float localX = spawn.LocalPosition.X;
+            float localY = spawn.LocalPosition.Y;
+            float groundZ = TerrainSurface.SampleZFromHeightmap(
+                source.Heightmap.Height,
+                heightTable,
+                landblockX,
+                landblockY,
+                localX,
+                localY);
+            var entity = new WorldEntity
+            {
+                Id = ProceduralSceneryIdAllocator.Allocate(
+                    landblockX,
+                    landblockY,
+                    ref sceneryCounter),
+                SourceGfxObjOrSetupId = spawn.ObjectId,
+                Position = new Vector3(
+                    localX,
+                    localY,
+                    groundZ + spawn.LocalPosition.Z)
+                    + worldOffset,
+                Rotation = spawn.Rotation,
+                MeshRefs = meshRefs,
+                Scale = spawn.Scale,
+                EffectCellId =
+                    TerrainSurface.ComputeOutdoorCellId(
+                        source.LandblockId,
+                        localX,
+                        localY),
+            };
+            if (bounds.TryGet(out Vector3 min, out Vector3 max))
+                entity.SetLocalBounds(min, max);
+            entities.Add(entity);
+        }
+        return entities;
+    }
+
     public static PhysicsDatBundle BuildDatBundle(
         IDatReaderWriter dats,
         uint landblockId,
@@ -247,6 +397,353 @@ public static class LandblockPhysicsContentBuilder
             envCellIds);
     }
 
+    public static TerrainSurface BuildTerrainSurface(
+        LoadedLandblock landblock,
+        ReadOnlySpan<float> heightTable)
+    {
+        ArgumentNullException.ThrowIfNull(landblock);
+        if (heightTable.Length < 256)
+        {
+            throw new ArgumentException(
+                "The retail terrain height table must contain at least 256 entries.",
+                nameof(heightTable));
+        }
+
+        uint landblockX = (landblock.LandblockId >> 24) & 0xFFu;
+        uint landblockY = (landblock.LandblockId >> 16) & 0xFFu;
+        var terrainBytes = new byte[81];
+        for (int index = 0; index < terrainBytes.Length; index++)
+        {
+            terrainBytes[index] =
+                (byte)(ushort)landblock.Heightmap.Terrain[index];
+        }
+        return new TerrainSurface(
+            landblock.Heightmap.Height,
+            heightTable,
+            landblockX,
+            landblockY,
+            terrainBytes);
+    }
+
+    public static void PublishPreparedCells(
+        PhysicsDataCache cache,
+        LoadedLandblock landblock,
+        LandblockCollisionBuild collisions,
+        Vector3 origin,
+        ICollection<CellSurface> cellSurfaces,
+        ICollection<PortalPlane> portalPlanes)
+    {
+        ArgumentNullException.ThrowIfNull(cache);
+        ArgumentNullException.ThrowIfNull(landblock);
+        ArgumentNullException.ThrowIfNull(collisions);
+        ArgumentNullException.ThrowIfNull(cellSurfaces);
+        ArgumentNullException.ThrowIfNull(portalPlanes);
+
+        PhysicsDatBundle dats =
+            landblock.PhysicsDats ?? PhysicsDatBundle.Empty;
+        uint count = dats.Info?.NumCells ?? 0u;
+        for (uint offset = 0; offset < count; offset++)
+        {
+            uint envCellId =
+                (landblock.LandblockId & 0xFFFF0000u)
+                | (0x0100u + offset);
+            if (!dats.EnvCells.TryGetValue(
+                    envCellId,
+                    out EnvCell? envCell)
+                || !collisions.CellStructures.TryGetValue(
+                    envCellId,
+                    out FlatCellStructureCollisionAsset? structure)
+                || !collisions.EnvCells.TryGetValue(
+                    envCellId,
+                    out FlatEnvCellTopology? topology))
+            {
+                continue;
+            }
+
+            Quaternion rotation = envCell.Position.Orientation;
+            Vector3 cellOriginWorld =
+                envCell.Position.Origin + origin;
+            Matrix4x4 transform =
+                Matrix4x4.CreateFromQuaternion(rotation)
+                * Matrix4x4.CreateTranslation(cellOriginWorld);
+            cache.CacheCellStruct(
+                envCellId,
+                envCell,
+                transform,
+                structure,
+                topology);
+
+            FlatPolygonTable portalPolygons =
+                structure.PortalPolygons;
+            for (int portalIndex = 0;
+                portalIndex < topology.Portals.Length;
+                portalIndex++)
+            {
+                FlatEnvCellPortal portal =
+                    topology.Portals[portalIndex];
+                if ((uint)portal.PolygonIndex
+                    >= (uint)portalPolygons.Polygons.Length)
+                {
+                    continue;
+                }
+                FlatCollisionPolygon polygon =
+                    portalPolygons.Polygons[portal.PolygonIndex];
+                if (polygon.VertexRange.Count < 3)
+                    continue;
+
+                var vertices =
+                    new Vector3[polygon.VertexRange.Count];
+                for (int index = 0; index < vertices.Length; index++)
+                {
+                    Vector3 local = portalPolygons.Vertices[
+                        polygon.VertexRange.Start + index];
+                    vertices[index] =
+                        Vector3.Transform(local, rotation)
+                        + cellOriginWorld;
+                }
+                portalPlanes.Add(PortalPlane.FromVertices(
+                    vertices.AsSpan(),
+                    portal.OtherCellId,
+                    envCellId & 0xFFFFu,
+                    portal.Flags));
+            }
+
+            cellSurfaces.Add(new CellSurface(
+                envCellId,
+                structure.PhysicsBsp.PolygonTable,
+                rotation,
+                cellOriginWorld));
+        }
+    }
+
+    public static void CacheBuildings(
+        PhysicsDataCache cache,
+        LoadedLandblock landblock,
+        TerrainSurface terrain,
+        Vector3 origin)
+    {
+        ArgumentNullException.ThrowIfNull(cache);
+        ArgumentNullException.ThrowIfNull(landblock);
+        ArgumentNullException.ThrowIfNull(terrain);
+        PhysicsDatBundle dats =
+            landblock.PhysicsDats ?? PhysicsDatBundle.Empty;
+        if (dats.Info is not { } info)
+            return;
+
+        uint prefix = landblock.LandblockId & 0xFFFF0000u;
+        foreach (BuildingInfo building in info.Buildings)
+        {
+            var portals =
+                new List<BldPortalInfo>(building.Portals.Count);
+            foreach (var portal in building.Portals)
+            {
+                portals.Add(new BldPortalInfo(
+                    prefix | (uint)portal.OtherCellId,
+                    unchecked((short)portal.OtherPortalId),
+                    (ushort)portal.Flags));
+            }
+
+            Vector3 buildingOrigin = building.Frame.Origin + origin;
+            Matrix4x4 transform =
+                Matrix4x4.CreateFromQuaternion(
+                    building.Frame.Orientation)
+                * Matrix4x4.CreateTranslation(buildingOrigin);
+            uint landcellId = prefix
+                | terrain.ComputeOutdoorCellId(
+                    building.Frame.Origin.X,
+                    building.Frame.Origin.Y);
+            uint shellPartZero = building.ModelId;
+            if ((shellPartZero & 0xFF000000u) == 0x02000000u)
+            {
+                dats.Setups.TryGetValue(
+                    building.ModelId,
+                    out Setup? setup);
+                shellPartZero =
+                    setup is not null && setup.Parts.Count > 0
+                        ? setup.Parts[0]
+                        : 0u;
+            }
+            cache.CacheBuilding(
+                landcellId,
+                portals,
+                transform,
+                shellPartZero);
+        }
+    }
+
+    public static void CachePreparedObjects(
+        PhysicsDataCache cache,
+        LandblockCollisionBuild collisions)
+    {
+        ArgumentNullException.ThrowIfNull(cache);
+        ArgumentNullException.ThrowIfNull(collisions);
+        foreach ((uint id, FlatGfxObjCollisionAsset asset) in
+            collisions.GfxObjs)
+        {
+            cache.CacheGfxObj(id, asset);
+        }
+        foreach ((uint id, FlatSetupCollision setup) in
+            collisions.Setups)
+        {
+            cache.CacheSetup(id, setup);
+        }
+    }
+
+    public static StaticCollisionPublication PublishStaticCollision(
+        PhysicsEngine engine,
+        PhysicsDataCache cache,
+        LoadedLandblock landblock,
+        LandblockCollisionBuild collisions,
+        Vector3 origin)
+    {
+        ArgumentNullException.ThrowIfNull(engine);
+        ArgumentNullException.ThrowIfNull(cache);
+        ArgumentNullException.ThrowIfNull(landblock);
+        ArgumentNullException.ThrowIfNull(collisions);
+
+        int bspOwners = 0;
+        int setupOwners = 0;
+        int noCollision = 0;
+        foreach (WorldEntity entity in landblock.Entities)
+        {
+            if (entity.IsBuildingShell)
+                continue;
+
+            IReadOnlyList<ShadowShape> bspShapes =
+                ShadowShapeBuilder.FromLandblockBspParts(
+                    entity.MeshRefs,
+                    entity.IsBuildingShell,
+                    cache.GetGfxObj);
+            if (bspShapes.Count > 0)
+            {
+                engine.ShadowObjects.RegisterMultiPart(
+                    entity.Id,
+                    entity.Position,
+                    entity.Rotation,
+                    bspShapes,
+                    0u,
+                    EntityCollisionFlags.None,
+                    worldOffsetX: origin.X,
+                    worldOffsetY: origin.Y,
+                    landblockId: landblock.LandblockId,
+                    seedCellId: entity.ParentCellId ?? 0u,
+                    isStatic: true);
+                bspOwners++;
+                continue;
+            }
+
+            FlatSetupCollision? setup =
+                cache.GetFlatSetup(
+                    entity.SourceGfxObjOrSetupId);
+            if (setup is null)
+            {
+                noCollision++;
+                continue;
+            }
+
+            float scale = entity.Scale > 0f ? entity.Scale : 1f;
+            var setupShapes = new List<ShadowShape>();
+            for (int index = 0;
+                index < setup.Cylinders.Length;
+                index++)
+            {
+                FlatCollisionCylinder cylinder =
+                    setup.Cylinders[index];
+                float radius = cylinder.Radius * scale;
+                float height = (cylinder.Height > 0f
+                    ? cylinder.Height
+                    : cylinder.Radius * 4f) * scale;
+                if (radius <= 0f)
+                    continue;
+                setupShapes.Add(new ShadowShape(
+                    entity.SourceGfxObjOrSetupId,
+                    cylinder.Origin * scale,
+                    Quaternion.Identity,
+                    scale,
+                    ShadowCollisionType.Cylinder,
+                    radius,
+                    height));
+            }
+
+            if (setup.Cylinders.Length == 0)
+            {
+                for (int index = 0;
+                    index < setup.Spheres.Length;
+                    index++)
+                {
+                    FlatCollisionSphere sphere = setup.Spheres[index];
+                    if (sphere.Radius <= 0f)
+                        continue;
+                    float radius = sphere.Radius * scale;
+                    Vector3 localOffset = sphere.Origin * scale;
+                    Vector3 localBaseOffset = localOffset
+                        + Vector3.Transform(
+                            -Vector3.UnitZ * radius,
+                            Quaternion.Inverse(entity.Rotation));
+                    setupShapes.Add(new ShadowShape(
+                        entity.SourceGfxObjOrSetupId,
+                        localBaseOffset,
+                        Quaternion.Identity,
+                        scale,
+                        ShadowCollisionType.Cylinder,
+                        radius,
+                        radius * 2f));
+                }
+            }
+
+            if (setup.Cylinders.Length == 0
+                && setup.Spheres.Length == 0
+                && setup.Radius > 0f)
+            {
+                float radius = setup.Radius * scale;
+                float height = (setup.Height > 0f
+                    ? setup.Height
+                    : setup.Radius * 2f) * scale;
+                setupShapes.Add(new ShadowShape(
+                    entity.SourceGfxObjOrSetupId,
+                    Vector3.Zero,
+                    Quaternion.Identity,
+                    scale,
+                    ShadowCollisionType.Cylinder,
+                    radius,
+                    height));
+            }
+
+            if (setupShapes.Count == 0)
+            {
+                noCollision++;
+                continue;
+            }
+            engine.ShadowObjects.RegisterMultiPart(
+                entity.Id,
+                entity.Position,
+                entity.Rotation,
+                setupShapes,
+                0u,
+                EntityCollisionFlags.None,
+                worldOffsetX: origin.X,
+                worldOffsetY: origin.Y,
+                landblockId: landblock.LandblockId,
+                seedCellId: entity.ParentCellId ?? 0u,
+                isStatic: true);
+            setupOwners++;
+        }
+
+        uint[] reflood =
+            engine.ShadowObjects.CaptureRefloodOwnersForLandblock(
+                landblock.LandblockId);
+        foreach (uint ownerId in reflood)
+        {
+            engine.ShadowObjects.RefloodOwnerForLandblock(
+                ownerId,
+                landblock.LandblockId);
+        }
+        return new StaticCollisionPublication(
+            bspOwners,
+            setupOwners,
+            noCollision);
+    }
+
     private static T Require<T>(
         PreparedCollisionReadResult<T> result,
         string kind,

src/AcDream.Core/Physics/TerrainSurface.cs

@@ -56,9 +56,25 @@ public sealed class TerrainSurface
     public TerrainSurface(byte[] heights, float[] heightTable,
         uint landblockX = 0, uint landblockY = 0,
         byte[]? terrainTypes = null)
+        : this(
+            heights,
+            (heightTable
+                ?? throw new ArgumentNullException(nameof(heightTable)))
+                .AsSpan(),
+            landblockX,
+            landblockY,
+            terrainTypes)
+    {
+    }
+
+    public TerrainSurface(
+        byte[] heights,
+        ReadOnlySpan<float> heightTable,
+        uint landblockX = 0,
+        uint landblockY = 0,
+        byte[]? terrainTypes = null)
     {
         ArgumentNullException.ThrowIfNull(heights);
-        ArgumentNullException.ThrowIfNull(heightTable);
         if (heights.Length < 81)
             throw new ArgumentException("heights must have 81 entries", nameof(heights));
         if (heightTable.Length < 256)
@@ -191,8 +207,25 @@ public sealed class TerrainSurface
         uint landblockX, uint landblockY,
         float localX, float localY)
     {
-        ArgumentNullException.ThrowIfNull(heights);
         ArgumentNullException.ThrowIfNull(heightTable);
+        return SampleZFromHeightmap(
+            heights,
+            heightTable.AsSpan(),
+            landblockX,
+            landblockY,
+            localX,
+            localY);
+    }
+
+    public static float SampleZFromHeightmap(
+        byte[] heights,
+        ReadOnlySpan<float> heightTable,
+        uint landblockX,
+        uint landblockY,
+        float localX,
+        float localY)
+    {
+        ArgumentNullException.ThrowIfNull(heights);
         if (heights.Length < 81)
             throw new ArgumentException("heights must have 81 entries", nameof(heights));
         if (heightTable.Length < 256)

src/AcDream.Headless/Hosting/HeadlessProcessContentOwner.cs

@@ -1,5 +1,7 @@
+using System.Collections.Immutable;
 using AcDream.Content;
 using AcDream.Headless.Configuration;
+using DatReaderWriter.DBObjs;
 
 namespace AcDream.Headless.Hosting;
 
@@ -25,7 +27,8 @@ internal interface IHeadlessProcessContentFactory
 internal sealed record HeadlessOpenedProcessContent(
     IDatReaderWriter Dats,
     IPreparedAssetSource Prepared,
-    MagicCatalog Magic);
+    MagicCatalog Magic,
+    ImmutableArray<float> HeightTable);
 
 internal sealed class ProductionHeadlessProcessContentFactory
     : IHeadlessProcessContentFactory
@@ -50,10 +53,24 @@ internal sealed class ProductionHeadlessProcessContentFactory
                 dats,
                 diagnostic);
             MagicCatalog magic = MagicCatalog.Load(dats);
+            Region region = dats.Get<Region>(0x13000000u)
+                ?? throw new InvalidOperationException(
+                    "Region dat id 0x13000000 is missing.");
+            float[]? sourceHeightTable =
+                region.LandDefs.LandHeightTable;
+            if (sourceHeightTable is null
+                || sourceHeightTable.Length < 256)
+            {
+                throw new InvalidOperationException(
+                    "Region.LandDefs.LandHeightTable is missing or truncated.");
+            }
+            ImmutableArray<float> heightTable =
+                ImmutableArray.CreateRange(sourceHeightTable);
             return new HeadlessOpenedProcessContent(
                 dats,
                 prepared,
-                magic);
+                magic,
+                heightTable);
         }
         catch
         {
@@ -80,6 +97,7 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
 {
     private readonly object _gate = new();
     private readonly MagicCatalog _magic;
+    private readonly ImmutableArray<float> _heightTable;
     private IDatReaderWriter? _dats;
     private IPreparedAssetSource? _prepared;
     private SharedPreparedCollisionCache? _collision;
@@ -105,8 +123,13 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
         IDatReaderWriter? dats = opened.Dats;
         IPreparedAssetSource? prepared = opened.Prepared;
         MagicCatalog? magic = opened.Magic;
+        ImmutableArray<float> heightTable = opened.HeightTable;
         bool incomplete =
-            dats is null || prepared is null || magic is null;
+            dats is null
+            || prepared is null
+            || magic is null
+            || heightTable.IsDefaultOrEmpty
+            || heightTable.Length < 256;
         if (incomplete || prepared is not IPreparedCollisionSource)
         {
             try
@@ -127,6 +150,7 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
         _dats = dats!;
         _prepared = prepared!;
         _magic = magic!;
+        _heightTable = heightTable;
         _collision = new SharedPreparedCollisionCache(
             (IPreparedCollisionSource)prepared!);
     }
@@ -149,7 +173,8 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
                 _dats!,
                 _prepared!,
                 _collision!,
-                _magic);
+                _magic,
+                _heightTable);
         }
     }
 
@@ -220,6 +245,7 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
         private readonly IPreparedAssetSource _prepared;
         private readonly IPreparedCollisionSource _collision;
         private readonly MagicCatalog _magic;
+        private readonly ImmutableArray<float> _heightTable;
 
         internal HeadlessProcessContentLease(
             HeadlessProcessContentOwner owner,
@@ -227,7 +253,8 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
             IDatReaderWriter dats,
             IPreparedAssetSource prepared,
             IPreparedCollisionSource collision,
-            MagicCatalog magic)
+            MagicCatalog magic,
+            ImmutableArray<float> heightTable)
         {
             _owner = owner;
             SessionId = sessionId;
@@ -235,6 +262,7 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
             _prepared = prepared;
             _collision = collision;
             _magic = magic;
+            _heightTable = heightTable;
         }
 
         internal string SessionId { get; }
@@ -275,6 +303,15 @@ internal sealed class HeadlessProcessContentOwner : IDisposable
             }
         }
 
+        internal ImmutableArray<float> HeightTable
+        {
+            get
+            {
+                ObjectDisposedException.ThrowIf(_owner is null, this);
+                return _heightTable;
+            }
+        }
+
         public void Dispose()
         {
             HeadlessProcessContentOwner? owner =

src/AcDream.Headless/Hosting/HeadlessProcessHost.cs

@@ -34,6 +34,7 @@ internal sealed class HeadlessProcessHost : IDisposable
             throw new HeadlessConfigurationException(
                 "Headless run mode requires at least one session.");
         }
+        HeadlessStaticStateAudit.ValidateProcessIsolation();
 
         _diagnostics = new HeadlessDiagnosticWriter(diagnostics);
         var credentials = new HeadlessCredentialResolver(
@@ -150,7 +151,9 @@ internal sealed class HeadlessProcessHost : IDisposable
             return HeadlessExitCode.RuntimeError;
         }
 
-        return HeadlessExitCode.Success;
+        return _scheduler.CaptureSnapshot().FaultedSessionCount > 0
+            ? HeadlessExitCode.RuntimeError
+            : HeadlessExitCode.Success;
     }
 
     public void Dispose()

src/AcDream.Headless/Hosting/HeadlessProcessScheduler.cs

@@ -75,9 +75,12 @@ internal sealed class HeadlessProcessScheduler
     internal HeadlessSchedulerSnapshot CaptureSnapshot()
     {
         int activeSessionCount = 0;
+        int faultedSessionCount = 0;
         for (int index = 0; index < _slots.Length; index++)
         {
-            if (!_slots[index].Session.IsPolicyComplete)
+            if (_slots[index].Session.IsFaulted)
+                faultedSessionCount++;
+            else if (!_slots[index].Session.IsPolicyComplete)
                 activeSessionCount++;
         }
 
@@ -87,6 +90,7 @@ internal sealed class HeadlessProcessScheduler
             Interlocked.Read(ref _turnCount),
             Interlocked.Read(ref _catchUpCollapseCount),
             activeSessionCount,
+            faultedSessionCount,
             NextDeadline());
     }
 
@@ -121,33 +125,41 @@ internal sealed class HeadlessProcessScheduler
             if (session.IsPolicyComplete)
                 continue;
 
-            if (session.IsReconnectPending)
+            try
             {
-                if (nowTimestamp < session.ReconnectDeadline)
+                if (session.IsReconnectPending)
+                {
+                    if (nowTimestamp < session.ReconnectDeadline)
+                        continue;
+
+                    RuntimeSessionStartResult result =
+                        session.CompletePendingReconnect(nowTimestamp);
+                    if (result.Status
+                        is not RuntimeSessionStartStatus.Connected)
+                    {
+                        throw result.Error
+                            ?? new InvalidOperationException(
+                                $"Headless session reconnect completed with {result.Status}.");
+                    }
+                    slot.LastTurnTimestamp = nowTimestamp;
+                    slot.NextDeadline = AddTicks(
+                        nowTimestamp,
+                        _periodTicks);
+                    dispatched = true;
+                    continue;
+                }
+
+                if (nowTimestamp < slot.NextDeadline)
                     continue;
 
-                RuntimeSessionStartResult result =
+                DispatchSessionDue(slot, nowTimestamp);
-                    session.CompletePendingReconnect(nowTimestamp);
+                dispatched = true;
-                if (result.Status
+            }
-                    is not RuntimeSessionStartStatus.Connected)
+            catch (Exception error)
-                {
+            {
-                    throw result.Error
+                session.Quarantine(error);
-                        ?? new InvalidOperationException(
-                            $"Headless session reconnect completed with {result.Status}.");
-                }
-                slot.LastTurnTimestamp = nowTimestamp;
-                slot.NextDeadline = AddTicks(
-                    nowTimestamp,
-                    _periodTicks);
                 dispatched = true;
-                continue;
             }
-
-            if (nowTimestamp < slot.NextDeadline)
-                continue;
-
-            DispatchSessionDue(slot, nowTimestamp);
-            dispatched = true;
         }
         return dispatched;
     }
@@ -246,4 +258,5 @@ internal readonly record struct HeadlessSchedulerSnapshot(
     long TurnCount,
     long CatchUpCollapseCount,
     int ActiveSessionCount,
+    int FaultedSessionCount,
     long NextDeadline);

src/AcDream.Headless/Hosting/HeadlessSessionHost.cs

@@ -124,6 +124,8 @@ internal sealed class HeadlessSessionHost : IDisposable
     private bool _reconnectPending;
     private ulong _stoppedGeneration;
     private string _accountName = string.Empty;
+    private Exception? _fault;
+    private bool _faulted;
     private bool _disposed;
 
     internal HeadlessSessionHost(
@@ -134,7 +136,8 @@ internal sealed class HeadlessSessionHost : IDisposable
         TimeProvider? timeProvider = null,
         TimeSpan? reconnectQuiescence = null,
         HeadlessProcessContentOwner.HeadlessProcessContentLease?
-            contentLease = null)
+            contentLease = null,
+        IHeadlessBotPolicy? policyOverride = null)
     {
         _descriptor = descriptor
             ?? throw new ArgumentNullException(nameof(descriptor));
@@ -235,8 +238,8 @@ internal sealed class HeadlessSessionHost : IDisposable
 
             hostLease = runtime.AcquireHostLease(
                 $"headless:{descriptor.Id}");
-            policy =
+            policy = policyOverride
-                HeadlessBotPolicyFactory.Create(descriptor.Policy.Id);
+                ?? HeadlessBotPolicyFactory.Create(descriptor.Policy.Id);
             policySubscription = runtime.Subscribe(policy);
             diagnostics.Lifecycle(
                 descriptor.Id,
@@ -264,7 +267,10 @@ internal sealed class HeadlessSessionHost : IDisposable
     internal string SessionId => _descriptor.Id;
     internal string ActiveCharacterName { get; private set; } =
         string.Empty;
-    internal bool IsPolicyComplete => _policy.IsComplete;
+    internal bool IsPolicyComplete =>
+        _faulted || _policy.IsComplete;
+    internal bool IsFaulted => _faulted;
+    internal Exception? Fault => _fault;
     internal bool IsReconnectPending => _reconnectPending;
     internal HeadlessProcessContentOwner.HeadlessProcessContentLease?
         Content => _contentLease;
@@ -296,6 +302,42 @@ internal sealed class HeadlessSessionHost : IDisposable
     internal RuntimeTeardownAcknowledgement Stop() =>
         Commands.Session.Stop(Runtime.Generation);
 
+    internal void Quarantine(Exception error)
+    {
+        ArgumentNullException.ThrowIfNull(error);
+        if (_faulted)
+            return;
+
+        _faulted = true;
+        _fault = error;
+        _reconnectPending = false;
+        _reconnectDeadline = 0L;
+        _diagnostics.Failure(
+            _descriptor.Id,
+            "quarantined",
+            error);
+        try
+        {
+            // A policy may have faulted from an event callback. Detach it
+            // before Runtime publishes teardown deltas so the quarantined
+            // observer cannot poison the canonical stop transaction.
+            _policySubscription.Dispose();
+            RuntimeTeardownAcknowledgement stopped = Stop();
+            if (!stopped.IsComplete)
+            {
+                _fault = new AggregateException(
+                    error,
+                    stopped.Error
+                    ?? new InvalidOperationException(
+                        $"Headless session '{_descriptor.Id}' did not quiesce after a fault."));
+            }
+        }
+        catch (Exception teardownError)
+        {
+            _fault = new AggregateException(error, teardownError);
+        }
+    }
+
     internal RuntimeSessionStartResult CompletePendingReconnect(
         long nowTimestamp)
     {
@@ -482,13 +524,18 @@ internal sealed class HeadlessSessionHost : IDisposable
     private LiveSessionEventRouter CreateEventRoute(
         AcDream.Core.Net.WorldSession session)
     {
+        IRuntimeDirectWorldProjection? worldProjection =
+            _contentLease is { } content
+                ? new HeadlessSessionWorldProjection(Runtime, content)
+                : null;
         var entities = new RuntimeLiveEntitySessionController(
             Runtime,
             session,
             message => _diagnostics.Message(
                 _descriptor.Id,
                 message,
-                Runtime.Generation.Value));
+                Runtime.Generation.Value),
+            worldProjection);
         return new LiveSessionEventRouter(
             session,
             entities.CreateSink(),

src/AcDream.Headless/Hosting/HeadlessSessionWorldProjection.cs

@@ -0,0 +1,433 @@
+using System.Numerics;
+using AcDream.Content;
+using AcDream.Core.Net.Messages;
+using AcDream.Core.Physics;
+using AcDream.Core.World;
+using AcDream.Runtime;
+using AcDream.Runtime.Entities;
+using AcDream.Runtime.Gameplay;
+using AcDream.Runtime.Physics;
+using AcDream.Runtime.Session;
+
+namespace AcDream.Headless.Hosting;
+
+internal interface IHeadlessCollisionNeighborhood
+{
+    void CenterOn(uint fullCellId);
+
+    bool IsReady(uint fullCellId);
+}
+
+/// <summary>
+/// Per-session mutable collision publication over process-shared immutable
+/// DAT and pak inputs. Every session retains its own engine, data cache,
+/// cell graph, shadow registry, and publication ledger.
+/// </summary>
+internal sealed class HeadlessCollisionNeighborhood
+    : IHeadlessCollisionNeighborhood
+{
+    private readonly GameRuntime _runtime;
+    private readonly HeadlessProcessContentOwner
+        .HeadlessProcessContentLease _content;
+    private readonly HashSet<uint> _resident = [];
+    private uint _centerLandblock;
+
+    internal HeadlessCollisionNeighborhood(
+        GameRuntime runtime,
+        HeadlessProcessContentOwner.HeadlessProcessContentLease content)
+    {
+        _runtime = runtime
+            ?? throw new ArgumentNullException(nameof(runtime));
+        _content = content
+            ?? throw new ArgumentNullException(nameof(content));
+    }
+
+    public void CenterOn(uint fullCellId)
+    {
+        uint center = CanonicalLandblock(fullCellId);
+        if (center == 0x0000FFFFu)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(fullCellId),
+                "A collision neighborhood requires a real destination cell.");
+        }
+        if (_centerLandblock == center
+            && _resident.Contains(center)
+            && _runtime.EntityObjects.Physics.Engine
+                .IsLandblockTerrainResident(center))
+        {
+            _runtime.EntityObjects.Physics.Engine
+                .UpdatePlayerCurrCell(fullCellId);
+            return;
+        }
+
+        RetireAll();
+        int centerX = (int)((center >> 24) & 0xFFu);
+        int centerY = (int)((center >> 16) & 0xFFu);
+        try
+        {
+            PublishOne(
+                center,
+                Vector3.Zero,
+                fullCellId,
+                required: true);
+            for (int dx = -1; dx <= 1; dx++)
+            {
+                for (int dy = -1; dy <= 1; dy++)
+                {
+                    if (dx == 0 && dy == 0)
+                        continue;
+                    int landblockX = centerX + dx;
+                    int landblockY = centerY + dy;
+                    if ((uint)landblockX > byte.MaxValue
+                        || (uint)landblockY > byte.MaxValue)
+                    {
+                        continue;
+                    }
+                    uint landblockId =
+                        ((uint)landblockX << 24)
+                        | ((uint)landblockY << 16)
+                        | 0xFFFFu;
+                    PublishOne(
+                        landblockId,
+                        new Vector3(dx * 192f, dy * 192f, 0f),
+                        fullCellId,
+                        required: false);
+                }
+            }
+            _centerLandblock = center;
+            _runtime.EntityObjects.Physics.Engine
+                .UpdatePlayerCurrCell(fullCellId);
+        }
+        catch
+        {
+            RetireAll();
+            throw;
+        }
+    }
+
+    public bool IsReady(uint fullCellId)
+    {
+        uint center = CanonicalLandblock(fullCellId);
+        if (_centerLandblock != center
+            || !_resident.Contains(center)
+            || !_runtime.EntityObjects.Physics.Engine
+                .IsLandblockTerrainResident(center))
+        {
+            return false;
+        }
+        return (fullCellId & 0xFFFFu) < 0x0100u
+            || _runtime.EntityObjects.Physics.DataCache
+                .GetCellStruct(fullCellId) is not null;
+    }
+
+    private void PublishOne(
+        uint landblockId,
+        Vector3 origin,
+        uint currentCellId,
+        bool required)
+    {
+        LoadedLandblock? source =
+            LandblockLoader.Load(_content.Dats, landblockId);
+        if (source is null)
+        {
+            if (required)
+            {
+                throw new InvalidDataException(
+                    $"Required headless landblock 0x{landblockId:X8} is missing.");
+            }
+            return;
+        }
+
+        IReadOnlyList<WorldEntity> staticEntities =
+            LandblockPhysicsContentBuilder.HydrateStaticEntities(
+                _content.Dats,
+                source,
+                origin,
+                includeVisualBounds: false);
+        IReadOnlyList<WorldEntity> scenery =
+            LandblockPhysicsContentBuilder.HydrateProceduralScenery(
+                _content.Dats,
+                source,
+                origin,
+                _content.HeightTable.AsSpan(),
+                includeVisualBounds: false);
+        var entities = new List<WorldEntity>(
+            staticEntities.Count + scenery.Count);
+        entities.AddRange(staticEntities);
+        entities.AddRange(scenery);
+        PhysicsDatBundle dats =
+            LandblockPhysicsContentBuilder.BuildDatBundle(
+                _content.Dats,
+                landblockId,
+                entities);
+        var landblock = new LoadedLandblock(
+            source.LandblockId,
+            source.Heightmap,
+            entities,
+            dats);
+        LandblockCollisionBuild collisions =
+            LandblockPhysicsContentBuilder
+                .BuildPreparedCollisionClosure(
+                    _content.PreparedCollision,
+                    landblock);
+
+        RuntimePhysicsState physics =
+            _runtime.EntityObjects.Physics;
+        PhysicsDataCache cache = physics.DataCache;
+        TerrainSurface terrain =
+            LandblockPhysicsContentBuilder.BuildTerrainSurface(
+                landblock,
+                _content.HeightTable.AsSpan());
+        var cellSurfaces = new List<CellSurface>();
+        var portalPlanes = new List<PortalPlane>();
+        LandblockPhysicsContentBuilder.PublishPreparedCells(
+            cache,
+            landblock,
+            collisions,
+            origin,
+            cellSurfaces,
+            portalPlanes);
+        LandblockPhysicsContentBuilder.CacheBuildings(
+            cache,
+            landblock,
+            terrain,
+            origin);
+        LandblockPhysicsContentBuilder.CachePreparedObjects(
+            cache,
+            collisions);
+
+        RuntimeCollisionAdmission admission =
+            physics.BeginCollisionAdmission(landblockId);
+        try
+        {
+            physics.AdmitCollisionAssets(
+                admission,
+                new RuntimeLandblockCollisionAssets(
+                    landblockId,
+                    terrain,
+                    cellSurfaces,
+                    portalPlanes,
+                    origin.X,
+                    origin.Y,
+                    currentCellId));
+            _ = LandblockPhysicsContentBuilder
+                .PublishStaticCollision(
+                    physics.Engine,
+                    cache,
+                    landblock,
+                    collisions,
+                    origin);
+            _ = physics.CompleteCollisionAdmission(admission);
+            _resident.Add(CanonicalLandblock(landblockId));
+        }
+        catch
+        {
+            _ = physics.WithdrawCollision(landblockId);
+            throw;
+        }
+    }
+
+    private void RetireAll()
+    {
+        if (_resident.Count == 0)
+        {
+            _centerLandblock = 0u;
+            return;
+        }
+
+        uint[] retiring = [.. _resident];
+        _resident.Clear();
+        _centerLandblock = 0u;
+        foreach (uint landblock in retiring)
+            _ = _runtime.EntityObjects.Physics.WithdrawCollision(landblock);
+    }
+
+    private static uint CanonicalLandblock(uint fullCellId) =>
+        (fullCellId & 0xFFFF0000u) | 0xFFFFu;
+}
+
+/// <summary>
+/// No-window projection of canonical Runtime entity and transit state into
+/// one local movement controller plus its per-session collision world.
+/// </summary>
+internal sealed class HeadlessSessionWorldProjection
+    : IRuntimeDirectWorldProjection
+{
+    private const float DefaultRadius = 0.48f;
+    private const float DefaultHeight = 1.835f;
+
+    private readonly GameRuntime _runtime;
+    private readonly IHeadlessCollisionNeighborhood _collision;
+    private readonly IPreparedCollisionSource? _preparedCollision;
+
+    internal HeadlessSessionWorldProjection(
+        GameRuntime runtime,
+        HeadlessProcessContentOwner.HeadlessProcessContentLease content)
+        : this(
+            runtime,
+            new HeadlessCollisionNeighborhood(runtime, content),
+            content.PreparedCollision)
+    {
+    }
+
+    internal HeadlessSessionWorldProjection(
+        GameRuntime runtime,
+        IHeadlessCollisionNeighborhood collision,
+        IPreparedCollisionSource? preparedCollision = null)
+    {
+        _runtime = runtime
+            ?? throw new ArgumentNullException(nameof(runtime));
+        _collision = collision
+            ?? throw new ArgumentNullException(nameof(collision));
+        _preparedCollision = preparedCollision;
+    }
+
+    public void ProjectSpawn(
+        RuntimeEntityRecord record,
+        bool isLocalPlayer)
+    {
+        if (isLocalPlayer)
+            SynchronizeLocalPlayer(record);
+    }
+
+    public void ProjectPosition(
+        RuntimeEntityRecord record,
+        bool isLocalPlayer)
+    {
+        if (isLocalPlayer)
+            SynchronizeLocalPlayer(record);
+    }
+
+    public void BeginTeleport()
+    {
+        if (_runtime.MovementOwner.Controller is { } controller)
+            controller.State = PlayerState.PortalSpace;
+    }
+
+    public RuntimeDestinationReadiness PrepareDestination(
+        long revealGeneration,
+        RuntimeTeleportDestination destination)
+    {
+        _collision.CenterOn(destination.CellId);
+        if (_runtime.EntityObjects.Entities.TryGetActive(
+                destination.EntityGuid,
+                out RuntimeEntityRecord record))
+        {
+            SynchronizeLocalPlayer(record);
+        }
+        if (_runtime.MovementOwner.Controller is { } controller)
+            controller.State = PlayerState.InWorld;
+
+        bool ready = _collision.IsReady(destination.CellId);
+        bool indoor = (destination.CellId & 0xFFFFu) >= 0x0100u;
+        return new RuntimeDestinationReadiness(
+            revealGeneration,
+            destination.CellId,
+            indoor,
+            IsUnhydratable: !ready,
+            RequiredRenderRadius: indoor ? 0 : 1,
+            IsRenderNeighborhoodReady: true,
+            AreCompositeTexturesReady: true,
+            IsCollisionReady: ready);
+    }
+
+    private void SynchronizeLocalPlayer(RuntimeEntityRecord record)
+    {
+        if (record.ServerGuid
+            != _runtime.PlayerIdentity.ServerGuid
+            || record.Snapshot.Position is not { } position)
+        {
+            return;
+        }
+
+        _collision.CenterOn(position.LandblockId);
+        PlayerMovementController controller =
+            _runtime.MovementOwner.Controller
+            ?? CreateController(record);
+        Vector3 wirePosition = new(
+            position.PositionX,
+            position.PositionY,
+            position.PositionZ);
+        Quaternion orientation = new(
+            position.RotationX,
+            position.RotationY,
+            position.RotationZ,
+            position.RotationW);
+
+        ResolveResult resolved =
+            _runtime.EntityObjects.Physics.Engine.Resolve(
+                wirePosition,
+                position.LandblockId,
+                Vector3.Zero,
+                100f);
+        ResolveResult placement =
+            _runtime.EntityObjects.Physics.Engine.ResolvePlacement(
+                resolved.Position,
+                resolved.CellId,
+                DefaultRadius,
+                DefaultHeight,
+                controller.StepUpHeight,
+                controller.StepDownHeight,
+                ObjectInfoState.IsPlayer
+                    | ObjectInfoState.EdgeSlide,
+                record.LocalEntityId ?? 0u);
+        if (placement.Ok)
+            resolved = placement;
+
+        controller.LocalEntityId = record.LocalEntityId ?? 0u;
+        controller.SetPosition(
+            resolved.Position,
+            resolved.CellId,
+            wirePosition);
+        controller.SetBodyOrientation(orientation);
+    }
+
+    private PlayerMovementController CreateController(
+        RuntimeEntityRecord record)
+    {
+        var controller = new PlayerMovementController(
+            _runtime.EntityObjects.Physics.Engine,
+            record.ObjectClock,
+            PlayerMovementConstructionOptions.From(
+                _runtime.CharacterOwner.MovementSkills.Snapshot));
+        controller.ApplyPhysicsState(record.FinalPhysicsState);
+        controller.LocalEntityId = record.LocalEntityId ?? 0u;
+        ApplySetupStepHeights(record, controller);
+        RuntimeMovementSkillProjection.ApplyTo(
+            _runtime.CharacterOwner.MovementSkills,
+            controller);
+        _runtime.MovementOwner.Controller = controller;
+        return controller;
+    }
+
+    private void ApplySetupStepHeights(
+        RuntimeEntityRecord record,
+        PlayerMovementController controller)
+    {
+        if (record.Snapshot.SetupTableId is not { } setupId
+            || (setupId & 0xFF000000u) != 0x02000000u
+            || _preparedCollision is null)
+        {
+            return;
+        }
+
+        PreparedCollisionReadResult<FlatSetupCollision> read =
+            _preparedCollision.ReadSetupCollision(setupId);
+        if (read.Status != PreparedAssetReadStatus.Loaded
+            || read.Data is not { } setup)
+        {
+            throw new InvalidDataException(
+                $"Player Setup collision 0x{setupId:X8} is {read.Status}.");
+        }
+        _runtime.EntityObjects.Physics.DataCache.CacheSetup(
+            setupId,
+            setup);
+        controller.StepUpHeight = setup.StepUpHeight > 0f
+            ? setup.StepUpHeight
+            : 0.4f;
+        controller.StepDownHeight = setup.StepDownHeight > 0f
+            ? setup.StepDownHeight
+            : 0.4f;
+    }
+}

src/AcDream.Headless/Hosting/HeadlessStaticStateAudit.cs

@@ -0,0 +1,49 @@
+using System.Reflection;
+using AcDream.Core.Physics;
+using AcDream.Headless.Configuration;
+
+namespace AcDream.Headless.Hosting;
+
+/// <summary>
+/// Rejects process-global physics probes whose mutable capture cursors and
+/// last-hit fields cannot be attributed safely when several Runtime roots
+/// share one process. Ordinary diagnostics remain session-labelled through
+/// <see cref="Diagnostics.HeadlessDiagnosticWriter"/>.
+/// </summary>
+internal static class HeadlessStaticStateAudit
+{
+    internal static void ValidateProcessIsolation()
+    {
+        var enabled = new List<string>();
+        foreach (PropertyInfo property in typeof(PhysicsDiagnostics)
+            .GetProperties(BindingFlags.Public | BindingFlags.Static)
+            .OrderBy(static property => property.Name, StringComparer.Ordinal))
+        {
+            if (property.PropertyType != typeof(bool)
+                || property.GetMethod is null
+                || (!property.Name.StartsWith(
+                        "Probe",
+                        StringComparison.Ordinal)
+                    && !property.Name.StartsWith(
+                        "Dump",
+                        StringComparison.Ordinal)))
+            {
+                continue;
+            }
+            if (property.GetValue(null) is true)
+                enabled.Add(property.Name);
+        }
+        if (PhysicsDiagnostics.CollisionShadowSampleEvery > 0)
+            enabled.Add(nameof(PhysicsDiagnostics.CollisionShadowSampleEvery));
+        if (PhysicsResolveCapture.IsEnabled)
+            enabled.Add(nameof(PhysicsResolveCapture));
+
+        if (enabled.Count != 0)
+        {
+            throw new HeadlessConfigurationException(
+                "Multi-session headless mode cannot use process-global "
+                + "physics probes. Disable: "
+                + string.Join(", ", enabled));
+        }
+    }
+}

src/AcDream.Runtime/Gameplay/PlayerMovementController.cs

@@ -972,7 +972,7 @@ public sealed class PlayerMovementController
     /// Install a complete authoritative frame rotation (spawn, teleport, or
     /// server correction) without collapsing it through the yaw projection.
     /// </summary>
-    internal void SetBodyOrientation(Quaternion orientation)
+    public void SetBodyOrientation(Quaternion orientation)
     {
         _body.Orientation = AcDream.Core.Physics.Motion.FrameOps.SetRotate(
             _body.Position,

src/AcDream.Runtime/Gameplay/RuntimeMovementSkillProjection.cs

@@ -0,0 +1,24 @@
+namespace AcDream.Runtime.Gameplay;
+
+/// <summary>
+/// Applies the exact server-owned run/jump snapshot to either host's one local
+/// movement controller. This lives beside the canonical skill owner so
+/// graphical and no-window construction cannot drift.
+/// </summary>
+public static class RuntimeMovementSkillProjection
+{
+    public static bool ApplyTo(
+        RuntimeMovementSkillState skills,
+        PlayerMovementController? controller)
+    {
+        ArgumentNullException.ThrowIfNull(skills);
+        RuntimeMovementSkillSnapshot snapshot = skills.Snapshot;
+        if (controller is null || !snapshot.IsComplete)
+            return false;
+
+        controller.SetCharacterSkills(
+            snapshot.RunSkill,
+            snapshot.JumpSkill);
+        return true;
+    }
+}

src/AcDream.Runtime/Session/RuntimeLiveEntitySessionController.cs

@@ -7,6 +7,23 @@ using AcDream.Runtime.World;
 
 namespace AcDream.Runtime.Session;
 
+public interface IRuntimeDirectWorldProjection
+{
+    void ProjectSpawn(
+        RuntimeEntityRecord record,
+        bool isLocalPlayer);
+
+    void ProjectPosition(
+        RuntimeEntityRecord record,
+        bool isLocalPlayer);
+
+    void BeginTeleport();
+
+    RuntimeDestinationReadiness PrepareDestination(
+        long revealGeneration,
+        RuntimeTeleportDestination destination);
+}
+
 /// <summary>
 /// Presentation-free inbound entity route for a direct Runtime host. It
 /// applies the same canonical identity, timestamp, object-table, and transit
@@ -18,15 +35,18 @@ public sealed class RuntimeLiveEntitySessionController
     private readonly GameRuntime _runtime;
     private readonly WorldSession _session;
     private readonly Action<string> _log;
+    private readonly IRuntimeDirectWorldProjection? _worldProjection;
 
     public RuntimeLiveEntitySessionController(
         GameRuntime runtime,
         WorldSession session,
-        Action<string>? log = null)
+        Action<string>? log = null,
+        IRuntimeDirectWorldProjection? worldProjection = null)
     {
         _runtime = runtime ?? throw new ArgumentNullException(nameof(runtime));
         _session = session ?? throw new ArgumentNullException(nameof(session));
         _log = log ?? (_ => { });
+        _worldProjection = worldProjection;
     }
 
     public LiveEntitySessionSink CreateSink() => new(
@@ -54,13 +74,20 @@ public sealed class RuntimeLiveEntitySessionController
             return;
 
         ulong integrationVersion = canonical.CreateIntegrationVersion;
-        _ = Entities.ApplyAcceptedSpawn(
+        bool applied = Entities.ApplyAcceptedSpawn(
             canonical,
             integrationVersion,
             canonical.Snapshot,
             replaceGeneration:
                 registration.Inbound.Disposition
                     is CreateObjectTimestampDisposition.NewGeneration);
+        if (applied)
+        {
+            _worldProjection?.ProjectSpawn(
+                canonical,
+                canonical.ServerGuid
+                    == _runtime.PlayerIdentity.ServerGuid);
+        }
     }
 
     private void OnDeleted(DeleteObject.Parsed delete)
@@ -146,6 +173,14 @@ public sealed class RuntimeLiveEntitySessionController
         _runtime.TransitOwner.OfferTeleportDestination(
             destination,
             timestamps.TeleportAdvanced);
+        if (Entities.Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord record))
+        {
+            _worldProjection?.ProjectPosition(
+                record,
+                isLocalPlayer: true);
+        }
         TryCompletePortal();
     }
 
@@ -174,6 +209,7 @@ public sealed class RuntimeLiveEntitySessionController
         RuntimeWorldTransitState transit = _runtime.TransitOwner;
         if (!transit.TryQueueTeleportStart(sequence))
             return;
+        _worldProjection?.BeginTeleport();
         if (!transit.ActivateQueuedTeleport())
         {
             throw new InvalidOperationException(
@@ -216,16 +252,21 @@ public sealed class RuntimeLiveEntitySessionController
             RuntimeWorldHostAcknowledgementStage.ProjectionRegistered);
 
         bool indoor = (destination.CellId & 0xFFFFu) >= 0x0100u;
+        RuntimeDestinationReadiness readiness =
+            _worldProjection?.PrepareDestination(
+                generation,
+                destination)
+            ?? new RuntimeDestinationReadiness(
+                generation,
+                destination.CellId,
+                indoor,
+                IsUnhydratable: false,
+                RequiredRenderRadius: indoor ? 0 : 1,
+                IsRenderNeighborhoodReady: true,
+                AreCompositeTexturesReady: true,
+                IsCollisionReady: true);
         if (!transit.AcknowledgeDestinationReadiness(
-                new RuntimeDestinationReadiness(
+                readiness))
-                    generation,
-                    destination.CellId,
-                    indoor,
-                    IsUnhydratable: false,
-                    RequiredRenderRadius: indoor ? 0 : 1,
-                    IsRenderNeighborhoodReady: true,
-                    AreCompositeTexturesReady: true,
-                    IsCollisionReady: true)))
         {
             throw new InvalidOperationException(
                 "Runtime rejected headless destination readiness.");

tests/AcDream.Headless.Tests/HeadlessProcessContentOwnerTests.cs

@@ -1,4 +1,6 @@
 using System.Reflection;
+using System.Collections.Immutable;
+using System.Runtime.InteropServices;
 using AcDream.Content;
 using AcDream.Headless.Configuration;
 using AcDream.Headless.Hosting;
@@ -114,6 +116,9 @@ public sealed class HeadlessProcessContentOwnerTests
         IPreparedCollisionSource sharedCollision =
             Assert.IsAssignableFrom<IPreparedCollisionSource>(
                 host.Sessions[0].Content?.PreparedCollision);
+        float[] sharedHeightTable = Assert.IsType<float[]>(
+            ImmutableCollectionsMarshal.AsArray(
+                host.Sessions[0].Content!.HeightTable));
         Assert.All(
             host.Sessions,
             session =>
@@ -130,6 +135,10 @@ public sealed class HeadlessProcessContentOwnerTests
                 Assert.Same(
                     sharedCollision,
                     session.Content?.PreparedCollision);
+                Assert.Same(
+                    sharedHeightTable,
+                    ImmutableCollectionsMarshal.AsArray(
+                        session.Content!.HeightTable));
             });
         Assert.Equal(
             sessionCount,
@@ -151,6 +160,13 @@ public sealed class HeadlessProcessContentOwnerTests
                     session.Runtime.EntityObjects.Physics.DataCache)
                 .Distinct(ReferenceEqualityComparer.Instance)
                 .Count());
+        Assert.Equal(
+            sessionCount,
+            host.Sessions
+                .Select(static session =>
+                    session.Runtime.MovementOwner)
+                .Distinct(ReferenceEqualityComparer.Instance)
+                .Count());
 
         HeadlessSessionHost[] sessions = host.Sessions.ToArray();
         host.Dispose();
@@ -223,7 +239,8 @@ public sealed class HeadlessProcessContentOwnerTests
             return new HeadlessOpenedProcessContent(
                 DatsResource,
                 PreparedResource,
-                MagicCatalog.Empty);
+                MagicCatalog.Empty,
+                ImmutableArray.CreateRange(new float[256]));
         }
     }
 }

tests/AcDream.Headless.Tests/HeadlessProcessSchedulerTests.cs

@@ -6,6 +6,7 @@ using AcDream.Headless.Credentials;
 using AcDream.Headless.Diagnostics;
 using AcDream.Headless.Hosting;
 using AcDream.Headless.Platform;
+using AcDream.Headless.Policies;
 using AcDream.Runtime;
 using AcDream.Runtime.Session;
 
@@ -186,11 +187,60 @@ public sealed class HeadlessProcessSchedulerTests
             StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void ThrowingPolicyQuarantinesOnlyItsOwnSession()
+    {
+        var time = new ManualTimeProvider();
+        var operations = new FixtureSessionOperations();
+        var throwing = new ThrowingPolicy();
+        var healthy = new CountingPolicy();
+        using HeadlessSessionHost first =
+            CreateSession(
+                "fault",
+                time,
+                operations,
+                policyOverride: throwing);
+        using HeadlessSessionHost second =
+            CreateSession(
+                "healthy",
+                time,
+                operations,
+                policyOverride: healthy);
+        Assert.Equal(
+            RuntimeSessionStartStatus.Connected,
+            first.Start().Status);
+        Assert.Equal(
+            RuntimeSessionStartStatus.Connected,
+            second.Start().Status);
+        var scheduler = new HeadlessProcessScheduler(
+            [first, second],
+            time);
+
+        time.Advance(TimeSpan.FromMilliseconds(15));
+        Assert.True(scheduler.DispatchDue(time.GetTimestamp()));
+
+        Assert.True(first.IsFaulted);
+        Assert.IsType<InvalidOperationException>(first.Fault);
+        Assert.False(second.IsFaulted);
+        Assert.Equal(1, healthy.TickCount);
+        HeadlessSchedulerSnapshot snapshot =
+            scheduler.CaptureSnapshot();
+        Assert.Equal(1, snapshot.FaultedSessionCount);
+        Assert.Equal(1, snapshot.ActiveSessionCount);
+
+        time.Advance(TimeSpan.FromMilliseconds(15));
+        Assert.True(scheduler.DispatchDue(time.GetTimestamp()));
+        Assert.Equal(2, healthy.TickCount);
+        Assert.Equal(1UL, first.Runtime.Clock.FrameNumber);
+        Assert.Equal(2UL, second.Runtime.Clock.FrameNumber);
+    }
+
     private static HeadlessSessionHost CreateSession(
         string id,
         TimeProvider time,
         ILiveSessionOperations operations,
-        TimeSpan? reconnectQuiescence = null)
+        TimeSpan? reconnectQuiescence = null,
+        IHeadlessBotPolicy? policyOverride = null)
     {
         var credential = new HeadlessCredentialSecret(
             $"{id}-credential",
@@ -203,7 +253,8 @@ public sealed class HeadlessProcessSchedulerTests
                 new HeadlessDiagnosticWriter(TextWriter.Null),
                 operations,
                 time,
-                reconnectQuiescence);
+                reconnectQuiescence,
+                policyOverride: policyOverride);
         }
         catch
         {
@@ -304,4 +355,67 @@ public sealed class HeadlessProcessSchedulerTests
             session.Dispose();
         }
     }
+
+    private abstract class FixturePolicy : IHeadlessBotPolicy
+    {
+        public virtual bool IsComplete => false;
+
+        public abstract void Tick(
+            IGameRuntimeView view,
+            IGameRuntimeCommands commands);
+
+        public void OnLifecycle(in RuntimeLifecycleDelta delta)
+        {
+        }
+
+        public void OnCommand(in RuntimeCommandDelta delta)
+        {
+        }
+
+        public void OnEntity(in RuntimeEntityDelta delta)
+        {
+        }
+
+        public void OnInventory(in RuntimeInventoryDelta delta)
+        {
+        }
+
+        public void OnChat(in RuntimeChatDelta delta)
+        {
+        }
+
+        public void OnMovement(in RuntimeMovementDelta delta)
+        {
+        }
+
+        public void OnPortal(in RuntimePortalDelta delta)
+        {
+        }
+
+        public void OnCombat(in RuntimeCombatDelta delta)
+        {
+        }
+
+        public void Dispose()
+        {
+        }
+    }
+
+    private sealed class ThrowingPolicy : FixturePolicy
+    {
+        public override void Tick(
+            IGameRuntimeView view,
+            IGameRuntimeCommands commands) =>
+            throw new InvalidOperationException("injected policy fault");
+    }
+
+    private sealed class CountingPolicy : FixturePolicy
+    {
+        public int TickCount { get; private set; }
+
+        public override void Tick(
+            IGameRuntimeView view,
+            IGameRuntimeCommands commands) =>
+            TickCount++;
+    }
 }

tests/AcDream.Headless.Tests/HeadlessSessionHostTests.cs

@@ -13,6 +13,7 @@ using AcDream.Runtime;
 using AcDream.Runtime.Entities;
 using AcDream.Runtime.Gameplay;
 using AcDream.Runtime.Session;
+using AcDream.Runtime.World;
 
 namespace AcDream.Headless.Tests;
 
@@ -186,6 +187,71 @@ public sealed class HeadlessSessionHostTests
         Assert.True(host.Runtime.CaptureOwnership().IsConverged);
     }
 
+    [Fact]
+    public void WorldProjectionHydratesCanonicalMovementAndTeleportState()
+    {
+        var operations = new FixtureSessionOperations();
+        using var credential = new HeadlessCredentialSecret(
+            "fixture",
+            "password");
+        using var host = new HeadlessSessionHost(
+            Descriptor(),
+            credential,
+            new HeadlessDiagnosticWriter(TextWriter.Null),
+            operations);
+        GameRuntime runtime = host.Runtime;
+        const uint player = 0x50000002u;
+        runtime.PlayerIdentity.ServerGuid = player;
+        AddFlatLandblock(runtime.EntityObjects.Physics.Engine);
+        RuntimeEntityRecord record = runtime.EntityObjects
+            .RegisterEntity(Spawn(player))
+            .Canonical!;
+        Assert.True(runtime.EntityObjects.ApplyAcceptedSpawn(
+            record,
+            record.CreateIntegrationVersion,
+            record.Snapshot,
+            replaceGeneration: false));
+        var collision = new FixtureCollisionNeighborhood();
+        var projection = new HeadlessSessionWorldProjection(
+            runtime,
+            collision);
+
+        projection.ProjectSpawn(record, isLocalPlayer: true);
+        PlayerMovementController controller =
+            Assert.IsType<PlayerMovementController>(
+                runtime.MovementOwner.Controller);
+        projection.ProjectPosition(record, isLocalPlayer: true);
+
+        Assert.Same(controller, runtime.MovementOwner.Controller);
+        Assert.Equal(record.LocalEntityId, controller.LocalEntityId);
+        Assert.Equal(
+            0xA9B40000u,
+            controller.CellId & 0xFFFF0000u);
+        Assert.True((controller.CellId & 0xFFFFu) < 0x0100u);
+        projection.BeginTeleport();
+        Assert.Equal(PlayerState.PortalSpace, controller.State);
+
+        RuntimeDestinationReadiness readiness =
+            projection.PrepareDestination(
+                revealGeneration: 7,
+                new RuntimeTeleportDestination(
+                    player,
+                    InstanceSequence: 1,
+                    PositionSequence: 2,
+                    TeleportSequence: 1,
+                    ForcePositionSequence: 0,
+                    new Position(
+                        0xA9B40001u,
+                        new Vector3(96f, 97f, 50f),
+                        Quaternion.Identity)));
+
+        Assert.True(readiness.IsCollisionReady);
+        Assert.False(readiness.IsUnhydratable);
+        Assert.Equal(PlayerState.InWorld, controller.State);
+        Assert.Equal(4, collision.CenterCount);
+        Assert.Equal(0xA9B40001u, collision.LastCell);
+    }
+
     private static HeadlessSessionDescriptor Descriptor(
         HeadlessCredentialProviderKind provider =
             HeadlessCredentialProviderKind.Environment,
@@ -217,18 +283,7 @@ public sealed class HeadlessSessionHostTests
     {
         const uint player = 0x50000002u;
         PhysicsEngine engine = runtime.EntityObjects.Physics.Engine;
-        var heights = new byte[81];
+        AddFlatLandblock(engine);
-        Array.Fill(heights, (byte)50);
-        var heightTable = new float[256];
-        for (int index = 0; index < heightTable.Length; index++)
-            heightTable[index] = index;
-        engine.AddLandblock(
-            0xA9B4FFFFu,
-            new TerrainSurface(heights, heightTable),
-            [],
-            [],
-            worldOffsetX: 0f,
-            worldOffsetY: 0f);
 
         RuntimeEntityRecord record = runtime.EntityObjects
             .RegisterEntity(Spawn(player))
@@ -246,6 +301,22 @@ public sealed class HeadlessSessionHostTests
         runtime.MovementOwner.Controller = controller;
     }
 
+    private static void AddFlatLandblock(PhysicsEngine engine)
+    {
+        var heights = new byte[81];
+        Array.Fill(heights, (byte)50);
+        var heightTable = new float[256];
+        for (int index = 0; index < heightTable.Length; index++)
+            heightTable[index] = index;
+        engine.AddLandblock(
+            0xA9B4FFFFu,
+            new TerrainSurface(heights, heightTable),
+            [],
+            [],
+            worldOffsetX: 0f,
+            worldOffsetY: 0f);
+    }
+
     private static WorldSession.EntitySpawn Spawn(uint guid)
     {
         var position = new CreateObject.ServerPosition(
@@ -389,4 +460,20 @@ public sealed class HeadlessSessionHostTests
         }
     }
 
+    private sealed class FixtureCollisionNeighborhood
+        : IHeadlessCollisionNeighborhood
+    {
+        public int CenterCount { get; private set; }
+        public uint LastCell { get; private set; }
+
+        public void CenterOn(uint fullCellId)
+        {
+            CenterCount++;
+            LastCell = fullCellId;
+        }
+
+        public bool IsReady(uint fullCellId) =>
+            fullCellId == LastCell;
+    }
+
 }

tests/AcDream.Headless.Tests/HeadlessSessionIsolationTests.cs

@@ -0,0 +1,376 @@
+using System.Net;
+using System.Reflection;
+using AcDream.Core.Net;
+using AcDream.Core.Net.Messages;
+using AcDream.Core.Physics;
+using AcDream.Headless.Configuration;
+using AcDream.Headless.Credentials;
+using AcDream.Headless.Diagnostics;
+using AcDream.Headless.Hosting;
+using AcDream.Runtime;
+using AcDream.Runtime.Entities;
+using AcDream.Runtime.Session;
+
+namespace AcDream.Headless.Tests;
+
+public sealed class HeadlessSessionIsolationTests
+{
+    [Theory]
+    [InlineData(1)]
+    [InlineData(5)]
+    [InlineData(10)]
+    public void SameServerIdentityStaysIsolatedAcrossActivityPortalAndReconnect(
+        int sessionCount)
+    {
+        const uint sharedPlayerGuid = 0x50000001u;
+        var operations = new FixtureOperations(sharedPlayerGuid);
+        HeadlessSessionHost[] hosts = Enumerable.Range(0, sessionCount)
+            .Select(index => CreateHost(index, operations))
+            .ToArray();
+        try
+        {
+            foreach (HeadlessSessionHost host in hosts)
+            {
+                Assert.Equal(
+                    RuntimeSessionStartStatus.Connected,
+                    host.Start().Status);
+            }
+
+            var firstRecords = new RuntimeEntityRecord[sessionCount];
+            for (int index = 0; index < hosts.Length; index++)
+            {
+                HeadlessSessionHost host = hosts[index];
+                WorldSession session =
+                    operations.ActiveSession(host.SessionId);
+                session.GameActionCapture = _ => { };
+                SpawnInto(session, sharedPlayerGuid, index + 1f);
+                RuntimeCommandResult selected =
+                    host.Commands.Selection.SelectObject(
+                        host.Runtime.Generation,
+                        sharedPlayerGuid);
+                Assert.True(selected.Accepted);
+                Assert.True(
+                    host.Runtime.EntityObjects.Entities.TryGetActive(
+                        sharedPlayerGuid,
+                        out RuntimeEntityRecord record));
+                firstRecords[index] = record;
+                Assert.Equal(
+                    index + 1f,
+                    record.Snapshot.Position!.Value.PositionX);
+
+                Portal(
+                    session,
+                    sharedPlayerGuid,
+                    index + 20f);
+                Assert.True(host.Runtime.Portal.Snapshot.Completed);
+                Assert.True(
+                    host.Runtime.TransitOwner
+                        .CaptureOwnership()
+                        .IsSessionIdle);
+            }
+
+            Assert.Equal(
+                sessionCount,
+                firstRecords
+                    .Distinct(ReferenceEqualityComparer.Instance)
+                    .Count());
+            Assert.Equal(
+                sessionCount,
+                hosts
+                    .Select(static host => host.Runtime.Entities)
+                    .Distinct(ReferenceEqualityComparer.Instance)
+                    .Count());
+
+            for (int index = 0; index < hosts.Length; index++)
+            {
+                HeadlessSessionHost host = hosts[index];
+                ulong priorGeneration = host.Runtime.Generation.Value;
+                Assert.Equal(
+                    RuntimeSessionStartStatus.Connected,
+                    host.Reconnect().Status);
+                Assert.True(
+                    host.Runtime.Generation.Value > priorGeneration);
+                Assert.Equal(0, host.Runtime.Entities.Count);
+
+                WorldSession replacement =
+                    operations.ActiveSession(host.SessionId);
+                replacement.GameActionCapture = _ => { };
+                SpawnInto(
+                    replacement,
+                    sharedPlayerGuid,
+                    index + 101f);
+                Assert.True(
+                    host.Runtime.EntityObjects.Entities.TryGetActive(
+                        sharedPlayerGuid,
+                        out RuntimeEntityRecord replacementRecord));
+                Assert.NotSame(firstRecords[index], replacementRecord);
+                Assert.Equal(
+                    index + 101f,
+                    replacementRecord.Snapshot.Position!.Value.PositionX);
+            }
+        }
+        finally
+        {
+            for (int index = hosts.Length - 1; index >= 0; index--)
+                hosts[index].Dispose();
+        }
+
+        Assert.Equal(sessionCount * 2, operations.CreatedSessionCount);
+        Assert.Equal(sessionCount * 2, operations.DisposedSessionCount);
+        Assert.All(
+            hosts,
+            static host =>
+                Assert.True(host.Runtime.CaptureOwnership().IsConverged));
+    }
+
+    private static HeadlessSessionHost CreateHost(
+        int index,
+        FixtureOperations operations)
+    {
+        string id = $"bot-{index}";
+        var credential = new HeadlessCredentialSecret(
+            $"{id}-credential",
+            "fixture-password");
+        try
+        {
+            return new HeadlessSessionHost(
+                new HeadlessSessionDescriptor
+                {
+                    Id = id,
+                    Endpoint = new HeadlessEndpointDescriptor
+                    {
+                        Host = "127.0.0.1",
+                        Port = 9000,
+                    },
+                    Account = id,
+                    Character = new HeadlessCharacterSelector
+                    {
+                        Index = 0,
+                    },
+                    Policy = new HeadlessBotPolicyDescriptor
+                    {
+                        Id = "idle",
+                    },
+                    Credential = new HeadlessCredentialReference
+                    {
+                        Provider =
+                            HeadlessCredentialProviderKind.StandardInput,
+                        Reference = $"{id}-credential",
+                    },
+                },
+                credential,
+                new HeadlessDiagnosticWriter(TextWriter.Null),
+                operations);
+        }
+        catch
+        {
+            credential.Dispose();
+            throw;
+        }
+    }
+
+    private static void SpawnInto(
+        WorldSession session,
+        uint guid,
+        float positionX) =>
+        EventDelegate<Action<WorldSession.EntitySpawn>>(
+            session,
+            nameof(session.EntitySpawned))(
+                Spawn(guid, positionX));
+
+    private static void Portal(
+        WorldSession session,
+        uint guid,
+        float positionX)
+    {
+        EventDelegate<Action<uint>>(
+            session,
+            nameof(session.TeleportStarted))(1u);
+        EventDelegate<Action<WorldSession.EntityPositionUpdate>>(
+            session,
+            nameof(session.PositionUpdated))(
+                new WorldSession.EntityPositionUpdate(
+                    guid,
+                    Position(positionX) with
+                    {
+                        LandblockId = 0x01020001u,
+                    },
+                    Velocity: null,
+                    PlacementId: null,
+                    IsGrounded: true,
+                    InstanceSequence: 1,
+                    PositionSequence: 2,
+                    TeleportSequence: 1,
+                    ForcePositionSequence: 0));
+    }
+
+    private static WorldSession.EntitySpawn Spawn(
+        uint guid,
+        float positionX)
+    {
+        CreateObject.ServerPosition position = Position(positionX);
+        var timestamps = new PhysicsTimestamps(
+            Position: 1,
+            Movement: 1,
+            State: 1,
+            Vector: 1,
+            Teleport: 0,
+            ServerControlledMove: 1,
+            ForcePosition: 0,
+            ObjDesc: 1,
+            Instance: 1);
+        var physics = new PhysicsSpawnData(
+            RawState: (uint)PhysicsStateFlags.ReportCollisions,
+            Position: position,
+            Movement: null,
+            AnimationFrame: null,
+            SetupTableId: 0x02000001u,
+            MotionTableId: null,
+            SoundTableId: null,
+            PhysicsScriptTableId: null,
+            Parent: null,
+            Children: null,
+            Scale: null,
+            Friction: null,
+            Elasticity: null,
+            Translucency: null,
+            Velocity: null,
+            Acceleration: null,
+            AngularVelocity: null,
+            DefaultScriptType: null,
+            DefaultScriptIntensity: null,
+            Timestamps: timestamps);
+        return new WorldSession.EntitySpawn(
+            guid,
+            position,
+            0x02000001u,
+            [],
+            [],
+            [],
+            null,
+            null,
+            "Headless",
+            null,
+            null,
+            null,
+            PhysicsState: physics.RawState,
+            InstanceSequence: 1,
+            MovementSequence: 1,
+            ServerControlSequence: 1,
+            PositionSequence: 1,
+            Physics: physics);
+    }
+
+    private static CreateObject.ServerPosition Position(float positionX) =>
+        new(
+            0x01010001u,
+            positionX,
+            10f,
+            5f,
+            1f,
+            0f,
+            0f,
+            0f);
+
+    private static TDelegate EventDelegate<TDelegate>(
+        WorldSession session,
+        string eventName)
+        where TDelegate : Delegate =>
+        Assert.IsType<TDelegate>(
+            typeof(WorldSession).GetField(
+                eventName,
+                BindingFlags.Instance | BindingFlags.NonPublic)
+            ?.GetValue(session));
+
+    private sealed class FixtureOperations(uint sharedPlayerGuid)
+        : ILiveSessionOperations
+    {
+        private readonly Dictionary<string, WorldSession> _active =
+            new(StringComparer.Ordinal);
+
+        public int CreatedSessionCount { get; private set; }
+        public int DisposedSessionCount { get; private set; }
+
+        public WorldSession ActiveSession(string account) =>
+            _active[account];
+
+        public IPEndPoint ResolveEndpoint(string host, int port) =>
+            new(IPAddress.Loopback, port);
+
+        public WorldSession CreateSession(IPEndPoint endpoint)
+        {
+            CreatedSessionCount++;
+            return new WorldSession(endpoint, new FixtureTransport());
+        }
+
+        public void Connect(
+            WorldSession session,
+            string user,
+            string password) =>
+            _active[user] = session;
+
+        public CharacterList.Parsed GetCharacters(
+            WorldSession session) =>
+            new(
+                0u,
+                [
+                    new CharacterList.Character(
+                        sharedPlayerGuid,
+                        "Headless",
+                        0u),
+                ],
+                [],
+                11,
+                "account",
+                true,
+                true);
+
+        public void EnterWorld(
+            WorldSession session,
+            int activeCharacterIndex)
+        {
+        }
+
+        public void Tick(WorldSession session)
+        {
+        }
+
+        public void DisposeSession(WorldSession session)
+        {
+            DisposedSessionCount++;
+            session.Dispose();
+        }
+    }
+
+    private sealed class FixtureTransport : IWorldSessionTransport
+    {
+        public void Send(ReadOnlySpan<byte> datagram)
+        {
+        }
+
+        public void Send(
+            IPEndPoint remote,
+            ReadOnlySpan<byte> datagram)
+        {
+        }
+
+        public int Receive(
+            Span<byte> destination,
+            TimeSpan timeout,
+            out IPEndPoint? from)
+        {
+            from = null;
+            return -1;
+        }
+
+        public ValueTask<NetReceiveResult> ReceiveAsync(
+            Memory<byte> destination,
+            CancellationToken cancellationToken) =>
+            ValueTask.FromException<NetReceiveResult>(
+                new OperationCanceledException(cancellationToken));
+
+        public void Dispose()
+        {
+        }
+    }
+}

tests/AcDream.Runtime.Tests/Session/RuntimeLiveEntitySessionControllerTests.cs

@@ -8,6 +8,7 @@ using AcDream.Core.Spells;
 using AcDream.Runtime.Entities;
 using AcDream.Runtime.Gameplay;
 using AcDream.Runtime.Session;
+using AcDream.Runtime.World;
 
 namespace AcDream.Runtime.Tests.Session;
 
@@ -102,6 +103,54 @@ public sealed class RuntimeLiveEntitySessionControllerTests
         Assert.Equal(0x01020001u, runtime.Portal.Snapshot.DestinationCell);
     }
 
+    [Fact]
+    public void DirectSinkProjectsAcceptedLocalWorldStateThroughOneHostSeam()
+    {
+        using GameRuntime runtime = CreateRuntime();
+        const uint playerGuid = 0x50000002u;
+        runtime.PlayerIdentity.ServerGuid = playerGuid;
+        using var session = new WorldSession(
+            new IPEndPoint(IPAddress.Loopback, 9000),
+            new FixtureTransport());
+        session.GameActionCapture = _ => { };
+        var projection = new FixtureWorldProjection();
+        var controller = new RuntimeLiveEntitySessionController(
+            runtime,
+            session,
+            worldProjection: projection);
+        LiveEntitySessionSink sink = controller.CreateSink();
+        WorldSession.EntitySpawn spawn =
+            Spawn(playerGuid, incarnation: 1);
+
+        sink.Spawned(spawn);
+        sink.TeleportStarted(1u);
+        sink.PositionUpdated(new WorldSession.EntityPositionUpdate(
+            playerGuid,
+            spawn.Position!.Value with
+            {
+                LandblockId = 0x01020001u,
+                PositionX = 30f,
+            },
+            Velocity: null,
+            PlacementId: null,
+            IsGrounded: true,
+            InstanceSequence: 1,
+            PositionSequence: 2,
+            TeleportSequence: 1,
+            ForcePositionSequence: 0));
+
+        Assert.Equal(1, projection.SpawnCount);
+        Assert.Equal(1, projection.PositionCount);
+        Assert.Equal(1, projection.TeleportStartCount);
+        Assert.Equal(1, projection.PrepareCount);
+        Assert.True(projection.LastSpawnWasLocal);
+        Assert.True(projection.LastPositionWasLocal);
+        Assert.Equal(playerGuid, projection.LastRecord?.ServerGuid);
+        Assert.Equal(0x01020001u, projection.LastDestination.CellId);
+        Assert.True(runtime.TransitOwner.CaptureOwnership().IsSessionIdle);
+        Assert.True(runtime.Portal.Snapshot.Completed);
+    }
+
     private static GameRuntime CreateRuntime()
     {
         var operations = new FixtureGameplayOperations();
@@ -211,6 +260,57 @@ public sealed class RuntimeLiveEntitySessionControllerTests
         }
     }
 
+    private sealed class FixtureWorldProjection
+        : IRuntimeDirectWorldProjection
+    {
+        public int SpawnCount { get; private set; }
+        public int PositionCount { get; private set; }
+        public int TeleportStartCount { get; private set; }
+        public int PrepareCount { get; private set; }
+        public bool LastSpawnWasLocal { get; private set; }
+        public bool LastPositionWasLocal { get; private set; }
+        public RuntimeEntityRecord? LastRecord { get; private set; }
+        public RuntimeTeleportDestination LastDestination { get; private set; }
+
+        public void ProjectSpawn(
+            RuntimeEntityRecord record,
+            bool isLocalPlayer)
+        {
+            SpawnCount++;
+            LastRecord = record;
+            LastSpawnWasLocal = isLocalPlayer;
+        }
+
+        public void ProjectPosition(
+            RuntimeEntityRecord record,
+            bool isLocalPlayer)
+        {
+            PositionCount++;
+            LastRecord = record;
+            LastPositionWasLocal = isLocalPlayer;
+        }
+
+        public void BeginTeleport() => TeleportStartCount++;
+
+        public RuntimeDestinationReadiness PrepareDestination(
+            long revealGeneration,
+            RuntimeTeleportDestination destination)
+        {
+            PrepareCount++;
+            LastDestination = destination;
+            bool indoor = (destination.CellId & 0xFFFFu) >= 0x0100u;
+            return new RuntimeDestinationReadiness(
+                revealGeneration,
+                destination.CellId,
+                indoor,
+                IsUnhydratable: false,
+                RequiredRenderRadius: indoor ? 0 : 1,
+                IsRenderNeighborhoodReady: true,
+                AreCompositeTexturesReady: true,
+                IsCollisionReady: true);
+        }
+    }
+
     private sealed class FixtureGameplayOperations
         : IRuntimeCombatAttackOperations,
           IRuntimeCombatTargetOperations,