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fix(scenery): add retail obj_within_block check for edge-boundary spawns

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Retail's CLandBlock::get_land_scenes creates a PhysicsObj for each
scenery spawn, then calls CPhysicsObj::obj_within_block (0x00461c30)
which verifies the model's sorting sphere stays within [r, 192-r] on
both axes. Edge-vertex spawns displaced close to the boundary (e.g.,
a tree at Y=190.97 from vertex y=8) get rejected because their sorting
sphere extends past the landblock edge.

We were missing this check, which caused a tree near a road at
~(85, 191) in landblock 0xA9B1 to appear in acdream but not retail.
The tree legitimately passed all other filters (road, building, slope)
but its Setup sorting sphere radius (~2-5m) meant it overflowed the
boundary.

Fix: look up each unique Setup's SortingSphere.Radius from the dat
(cached per objectId) and apply the within-block bounds check after
the slope filter, matching retail's order. GfxObj objects (0x01) use
radius 0 (permissive) since they're typically small single-mesh items.

Also: remove temporary ACDREAM_SCENERY_DIAG logging, fix duplicate
xmldoc on IsOnRoad, update road check reference to named-retail PDB
symbol (CLandBlock::on_road at 0x0052FFF0).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Erik 2026-05-08 07:44:17 +02:00
parent 833d167ebc
commit e8aa1c82f4
1 changed files with 59 additions and 11 deletions
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70
src/AcDream.Core/World/SceneryGenerator.cs
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@ -59,6 +59,7 @@ public static class SceneryGenerator
float[]? heightTable = null)
{
var result = new List<ScenerySpawn>();
var sortingRadiusCache = new Dictionary<uint, float>();
if (region.TerrainInfo?.TerrainTypes is null || region.SceneInfo?.SceneTypes is null)
return result;
@ -182,6 +183,15 @@ public static class SceneryGenerator
if (nz < obj.MinSlope || nz > obj.MaxSlope) continue;
}
// Retail obj_within_block check: the model's sorting sphere must
// fit entirely within the landblock bounds. This rejects edge-vertex
// spawns whose bounding sphere would extend past the boundary.
// Named-retail: CPhysicsObj::obj_within_block (0x00461c30), called
// inside CLandBlock::get_land_scenes after find_terrain_poly/CheckSlope.
float sortRadius = GetSortingSphereRadius(dats, obj.ObjectId, sortingRadiusCache);
if (!IsWithinBlock(lx, ly, sortRadius))
continue;
// BaseLoc.Z offset: scenery-specific vertical offset from
// the ground (e.g., flowers planted at -0.1m so they
// don't float above grass). The renderer adds groundZ
@ -262,20 +272,10 @@ public static class SceneryGenerator
/// </summary>
private const float RoadHalfWidth = 5.0f;
/// <summary>
/// Retail-faithful post-displacement road test. Ported from ACViewer
/// Landblock.OnRoad (Physics/Common/Landblock.cs lines 300-398), which is
/// a direct port of FUN_00530d30 in the retail client.
///
/// Examines the 4 corners of the cell containing (lx, ly) and, depending
/// on how many are road vertices (0, 1, 2, 3, or 4), applies a polygonal
/// test using the 5-unit road half-width to check if (lx, ly) lies on the
/// road ribbon. Returns true if the point is on a road.
/// </summary>
/// <summary>
/// Retail-faithful road ribbon test — direct port of ACViewer's
/// Landblock.OnRoad (Physics/Common/Landblock.cs lines 300-398), which
/// itself is a port of FUN_00530d30 in acclient.exe.
/// itself is a port of CLandBlock::on_road (named-retail 0x0052FFF0).
///
/// Classifies the 4 corners of the cell containing (lx, ly) by road type
/// (bits 0-1 of the terrain word) and applies a different geometric test
@ -370,6 +370,54 @@ public static class SceneryGenerator
private const int CellsPerSide = 8;
/// <summary>
/// Retail CPhysicsObj::obj_within_block check — verifies the object's sorting
/// sphere stays entirely within the landblock bounds. Returns true if the object
/// is within bounds.
///
/// Named-retail: CPhysicsObj::obj_within_block (0x00461c30).
/// ACViewer: PhysicsObj.obj_within_block.
///
/// Retail loads the full PhysicsObj, transforms the sorting sphere center via
/// LocalToGlobal, then checks center ± radius against [0, BlockLength].
/// We approximate by ignoring the sorting sphere center offset (typically small
/// for scenery) and checking the spawn position directly against [radius, 192-radius].
/// </summary>
private static bool IsWithinBlock(float lx, float ly, float sortingSphereRadius)
{
if (sortingSphereRadius <= 0f) return true;
return lx >= sortingSphereRadius && ly >= sortingSphereRadius
&& lx < LandblockSize - sortingSphereRadius
&& ly < LandblockSize - sortingSphereRadius;
}
/// <summary>
/// Gets the sorting sphere radius for a scenery object, with caching.
/// Setup objects (0x02xxxxxx) use Setup.SortingSphere.Radius.
/// GfxObj objects (0x01xxxxxx) fall back to 0 (allows placement; these are
/// typically small items like grass patches whose BSP sphere is tiny).
/// </summary>
private static float GetSortingSphereRadius(
DatCollection dats, uint objectId, Dictionary<uint, float> cache)
{
if (cache.TryGetValue(objectId, out float cached))
return cached;
float radius = 0f;
if ((objectId >> 24) == 0x02)
{
// Setup — has an explicit SortingSphere
var setup = dats.Get<Setup>(objectId);
if (setup?.SortingSphere is { } sphere)
radius = sphere.Radius;
}
// GfxObj (0x01) — no Setup.SortingSphere; use 0 (permissive).
// These are typically small single-mesh scenery items.
cache[objectId] = radius;
return radius;
}
/// <summary>
/// Pseudo-random displacement within a cell for a scenery object. Returns a
/// Vector3 in local cell-offset space (the caller adds it to the cell corner