From e3c36b5bf87ad9c7ea722e122c55f48c71aa294b Mon Sep 17 00:00:00 2001
From: Erik <erik.nihlen@gmail.com>
Date: Fri, 8 May 2026 07:53:04 +0200
Subject: [PATCH] =?UTF-8?q?revert:=20remove=20obj=5Fwithin=5Fblock=20?=
 =?UTF-8?q?=E2=80=94=20sorting=20sphere=20radii=20too=20large?=
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The obj_within_block check using Setup.SortingSphere.Radius rejects
far too many spawns. Sorting spheres for trees are 5-10m, creating
a wide exclusion zone around every landblock edge. WorldBuilder
produces correct scenery with just bounds+road+building+slope checks
and no bounding sphere check. Revert to match WorldBuilder's approach.

The single extra tree near the road at vtx=(4,8) in 0xA9B1 remains
as a known minor discrepancy from retail — root cause TBD.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/AcDream.Core/World/SceneryGenerator.cs | 58 ----------------------
 1 file changed, 58 deletions(-)

diff --git a/src/AcDream.Core/World/SceneryGenerator.cs b/src/AcDream.Core/World/SceneryGenerator.cs
index d4ae229..a5dc0ce 100644
--- a/src/AcDream.Core/World/SceneryGenerator.cs
+++ b/src/AcDream.Core/World/SceneryGenerator.cs
@@ -59,7 +59,6 @@ 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;
@@ -183,15 +182,6 @@ 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
@@ -370,54 +360,6 @@ 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