Addressing PR comments

Author: david-lively

CHANGES.md

@@ -5,7 +5,11 @@
 ##### Additions :tada:
 
 - Added option to ignore the `KHR_material_unlit` extension to force default lighting on tilesets. 
-- Moved flat normal generation into `CesiumDefaultTilesetShader` pixel shader. Custom lit materials should expose a boolean property `computeFlatNormals` and generate normals accordingly. 
+
+##### Breaking Changes :mega:
+
+- Flat normals are now computed in `CesiumDefaultTilesetShader` to avoid duplicating vertices as tiles are loaded. Existing copies of this shader should incorporate this logic using the boolean `computeFlatNormals` property to maintain a correct appearance.
+
 
 ## v1.17.0 - 2025-08-01
 

Editor/Cesium3DTilesetEditor.cs

@@ -422,9 +422,9 @@ private void DrawRenderProperties()
                 "Generate Smooth Normals",
                 "Whether to generate smooth normals when normals are missing in the glTF." +
                 "\n\n" +
-                "This option allows the glTFs to be rendered with smooth normals when the " +
-                " original glTF is missing normals. If normals are missing and this option " +
-                "is not enabled, flat normals should be generated in the shader. "
+                "This option allows glTFs to be rendered with smooth normals when the original glTF " +
+                "is missing normals. If this option is not enabled and normals are missing, " +
+                "flat normals will be generated in the shader. "
                 );
             EditorGUILayout.PropertyField(this._generateSmoothNormals, generateSmoothNormalsContent);
 

Runtime/Cesium3DTileset.cs

@@ -575,8 +575,7 @@ public Material opaqueMaterial
         /// </summary>
         /// <remarks>
         /// This option allows the glTFs to be rendered with smooth normals instead when the original glTF is missing normals. 
-        /// If normals are missing and this option is not enabled, flat normals should be generated
-        /// in the shader. 
+        /// If normals are missing and this option is not enabled, flat normals will be generated in the shader. 
         /// </remarks>
         public bool generateSmoothNormals
         {

Runtime/Resources/CesiumDefaultTilesetMaterial.mat

@@ -100,7 +100,7 @@ Material:
     - _AlphaCutoffEnable: 1
     - _AlphaDstBlend: 0
     - _AlphaSrcBlend: 1
-    - _AlphaToMask: 1
+    - _AlphaToMask: 0
     - _AlphaToMaskInspectorValue: 0
     - _BUILTIN_AlphaClip: 1
     - _BUILTIN_Blend: 0

Runtime/Resources/CesiumDefaultTilesetShader.shadergraph

@@ -3226,7 +3226,7 @@
         "else"
     ],
     "m_Precision": 0,
-    "m_PreviewExpanded": false,
+    "m_PreviewExpanded": true,
     "m_DismissedVersion": 0,
     "m_PreviewMode": 0,
     "m_CustomColors": {
@@ -3262,7 +3262,7 @@
         "m_Position": {
             "serializedVersion": "2",
             "x": 2038.0,
-            "y": -219.0,
+            "y": -220.0,
             "width": 132.0,
             "height": 94.0
         }
@@ -5998,10 +5998,10 @@
         "m_Expanded": true,
         "m_Position": {
             "serializedVersion": "2",
-            "x": 2202.0,
-            "y": -221.0,
+            "x": 2199.0,
+            "y": -220.0,
             "width": 211.0,
-            "height": 157.00001525878907
+            "height": 157.0
         }
     },
     "m_Slots": [
@@ -7640,7 +7640,7 @@
     "m_Title": "Compute Flat Normals",
     "m_Position": {
         "x": 1465.0,
-        "y": -280.0
+        "y": -279.0
     }
 }
 
@@ -8227,7 +8227,7 @@
     "m_Title": "glTF PBR Metallic-Roughness",
     "m_Position": {
         "x": -1865.0,
-        "y": 1692.0001220703125
+        "y": 1692.0
     }
 }
 
@@ -9591,8 +9591,8 @@
         "m_Expanded": true,
         "m_Position": {
             "serializedVersion": "2",
-            "x": 1885.0,
-            "y": -219.0,
+            "x": 1882.0,
+            "y": -220.0,
             "width": 130.0,
             "height": 118.0
         }
@@ -10121,10 +10121,10 @@
         "m_Expanded": true,
         "m_Position": {
             "serializedVersion": "2",
-            "x": -1539.60009765625,
-            "y": 1179.2000732421875,
+            "x": -1540.0,
+            "y": 1179.0,
             "width": 356.0,
-            "height": 95.2000732421875
+            "height": 95.0
         }
     },
     "m_Slots": [
@@ -10612,7 +10612,7 @@
     "m_Title": "glTF Emissive Texture",
     "m_Position": {
         "x": -1865.0,
-        "y": 2351.999755859375
+        "y": 2352.0
     }
 }
 
@@ -10729,9 +10729,9 @@
         "m_Position": {
             "serializedVersion": "2",
             "x": 2079.0,
-            "y": -13.99997615814209,
+            "y": -13.999979019165039,
             "width": 186.0,
-            "height": 33.999969482421878
+            "height": 33.99996566772461
         }
     },
     "m_Slots": [
@@ -14371,7 +14371,7 @@
     "m_Title": "glTF Normal Texture",
     "m_Position": {
         "x": -1868.0,
-        "y": 947.0001220703125
+        "y": 947.0
     }
 }
 

native~/Runtime/src/UnityPrepareRendererResources.cpp

@@ -112,7 +112,6 @@ template <typename TIndex> struct CopyVertexColors {
   uint8_t* pWritePos;
   size_t stride;
   size_t vertexCount;
-  bool duplicateVertices;
   TIndex* indices;
 
   struct Color32 {
@@ -130,28 +129,14 @@ template <typename TIndex> struct CopyVertexColors {
     }
 
     bool success = true;
-    if (duplicateVertices) {
-      for (size_t i = 0; success && i < vertexCount; ++i) {
-        TIndex vertexIndex = indices[i];
-        if (vertexIndex < 0 || vertexIndex >= colorView.size()) {
-          success = false;
-        } else {
-          Color32& packedColor = *reinterpret_cast<Color32*>(pWritePos);
-          success = CopyVertexColors::convertColor(
-              colorView[vertexIndex],
-              packedColor);
-          pWritePos += stride;
-        }
-      }
-    } else {
-      for (size_t i = 0; success && i < vertexCount; ++i) {
-        if (i >= colorView.size()) {
-          success = false;
-        } else {
-          Color32& packedColor = *reinterpret_cast<Color32*>(pWritePos);
-          success = CopyVertexColors::convertColor(colorView[i], packedColor);
-          pWritePos += stride;
-        }
+
+    for (size_t i = 0; success && i < vertexCount; ++i) {
+      if (i >= colorView.size()) {
+        success = false;
+      } else {
+        Color32& packedColor = *reinterpret_cast<Color32*>(pWritePos);
+        success = CopyVertexColors::convertColor(colorView[i], packedColor);
+        pWritePos += stride;
       }
     }
 
@@ -563,8 +548,6 @@ void loadPrimitive(
             pBufferStart + colorByteOffset,
             stride,
             static_cast<size_t>(vertexCount),
-            // computeFlatNormals,
-            false,
             indices});
   }
 

native~/Runtime/src/UnityPrepareRendererResources.h

@@ -50,8 +50,8 @@ struct CesiumPrimitiveInfo {
 
   /**
    * @brief Whether the primitive contains normals
-   * @remarks If normals are not present amd using a lit material, they should
-   * be generated on the CPU or in the shader.
+   * @remarks If normals are not present and using a lit material,
+   * they should be generated on the CPU or in the material's shader.
    */
   bool hasNormals = false;