added splat indexes to vertex attributes

updates geometry pipeline stage to use modelutility to find attributes
CesiumGS · Jan 24, 2025 · 933c3e3 · 933c3e3
1 parent 8183132
commit 933c3e3
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Showing 2 changed files with 33 additions and 10 deletions.
diff --git a/packages/engine/Source/Scene/Model/GeometryPipelineStage.js b/packages/engine/Source/Scene/Model/GeometryPipelineStage.js
@@ -143,18 +143,27 @@ GeometryPipelineStage.process = function (
       model?.style?.showGaussianSplatting ?? model.showGaussianSplatting;
 
     if (gaussianSplatsEnabled === true) {
-      primitive.attributes.find((a) => a.name === "POSITION").instanceDivisor =
-        showSplats ? 1 : 0;
-      primitive.attributes.find((a) => a.name === "_SCALE").instanceDivisor =
-        showSplats ? 1 : 0;
-      primitive.attributes.find((a) => a.name === "_ROTATION").instanceDivisor =
-        showSplats ? 1 : 0;
-      primitive.attributes.find((a) => a.name === "COLOR_0").instanceDivisor =
-        showSplats ? 1 : 0;
+      ModelUtility.getAttributeBySemantic(
+        primitive,
+        VertexAttributeSemantic.POSITION,
+      ).instanceDivisor = showSplats ? 1 : 0;
+      ModelUtility.getAttributeBySemantic(
+        primitive,
+        VertexAttributeSemantic.SCALE,
+      ).instanceDivisor = showSplats ? 1 : 0;
+      ModelUtility.getAttributeBySemantic(
+        primitive,
+        VertexAttributeSemantic.ROTATION,
+      ).instanceDivisor = showSplats ? 1 : 0;
+      ModelUtility.getAttributeBySemantic(
+        primitive,
+        VertexAttributeSemantic.COLOR,
+      ).instanceDivisor = showSplats ? 1 : 0;
 
       if (primitive.hasGaussianSplatTexture) {
-        primitive.attributes.find(
-          (a) => a.name === "_SPLAT_INDEXES",
+        ModelUtility.getAttributeBySemantic(
+          primitive,
+          VertexAttributeSemantic.SPLAT_INDEXES,
         ).instanceDivisor = showSplats ? 1 : 0;
       }
 

diff --git a/packages/engine/Source/Scene/VertexAttributeSemantic.js b/packages/engine/Source/Scene/VertexAttributeSemantic.js
@@ -87,6 +87,13 @@ const VertexAttributeSemantic = {
    * @constant
    */
   ROTATION: "_ROTATION",
+  /**
+   * Gaussian Splat Attribute Texture Index
+   *
+   * @type {string}
+   * @constant
+   */
+  SPLAT_INDEXES: "_SPLAT_INDEXES",
 };
 
 function semanticToVariableName(semantic) {
@@ -111,6 +118,8 @@ function semanticToVariableName(semantic) {
       return "scale";
     case VertexAttributeSemantic.ROTATION:
       return "rotation";
+    case VertexAttributeSemantic.SPLAT_INDEXES:
+      return "splatIndex";
     //>>includeStart('debug', pragmas.debug);
     default:
       throw new DeveloperError("semantic is not a valid value.");
@@ -144,6 +153,7 @@ VertexAttributeSemantic.hasSetIndex = function (semantic) {
     case VertexAttributeSemantic.FEATURE_ID:
     case VertexAttributeSemantic.SCALE:
     case VertexAttributeSemantic.ROTATION:
+    case VertexAttributeSemantic.SPLAT_INDEXES:
       return true;
     //>>includeStart('debug', pragmas.debug);
     default:
@@ -196,6 +206,8 @@ VertexAttributeSemantic.fromGltfSemantic = function (gltfSemantic) {
       return VertexAttributeSemantic.SCALE;
     case "_ROTATION":
       return VertexAttributeSemantic.ROTATION;
+    case "_SPLAT_INDEXES":
+      return VertexAttributeSemantic.SPLAT_INDEXES;
   }
 
   return undefined;
@@ -269,6 +281,8 @@ VertexAttributeSemantic.getGlslType = function (semantic) {
       return "vec3";
     case VertexAttributeSemantic.ROTATION:
       return "vec4";
+    case VertexAttributeSemantic.SPLAT_INDEXES:
+      return "int";
     //>>includeStart('debug', pragmas.debug);
     default:
       throw new DeveloperError("semantic is not a valid value.");