Truncate the bone matrix indices as Draco can return not exact values

src/Mesh/Compression/babylon.dracoCompression.ts

@@ -75,12 +75,16 @@ module BABYLON {
                     const attribute = decoder.GetAttributeByUniqueId(geometry, uniqueId);
                     const dracoData = new dracoModule.DracoFloat32Array();
                     try {
+                        if (attribute.num_components() !== VertexBuffer.DeduceStride(kind)) {
+                            throw new Error(`Unsupported number of components for ${kind}`);
+                        }
+
                         decoder.GetAttributeFloatForAllPoints(geometry, attribute, dracoData);
-                        const data = new Float32Array(numPoints * VertexBuffer.DeduceStride(kind));
-                        for (let i = 0; i < data.length; i++) {
-                            data[i] = dracoData.GetValue(i);
+                        const babylonData = new Float32Array(numPoints * attribute.num_components());
+                        for (let i = 0; i < babylonData.length; i++) {
+                            babylonData[i] = dracoData.GetValue(i);
                         }
-                        vertexData.set(data, kind);
+                        vertexData.set(babylonData, kind);
                     }
                     finally {
                         dracoModule.destroy(dracoData);

src/Mesh/babylon.mesh.ts

@@ -804,14 +804,14 @@
                         for (inf = 0; inf < 4; inf++) {
                             weight = matricesWeightsData[matWeightIdx + inf];
                             if (weight <= 0) break;
-                            Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, matricesIndicesData[matWeightIdx + inf] * 16, weight, tempMatrix);
+                            Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, Math.floor(matricesIndicesData[matWeightIdx + inf] * 16), weight, tempMatrix);
                             finalMatrix.addToSelf(tempMatrix);
                         }
                         if (needExtras) {
                             for (inf = 0; inf < 4; inf++) {
                                 weight = matricesWeightsExtraData![matWeightIdx + inf];
                                 if (weight <= 0) break;
-                                Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, matricesIndicesExtraData![matWeightIdx + inf] * 16, weight, tempMatrix);
+                                Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, Math.floor(matricesIndicesExtraData![matWeightIdx + inf] * 16), weight, tempMatrix);
                                 finalMatrix.addToSelf(tempMatrix);
                             }
                         }
@@ -3266,7 +3266,7 @@
                 for (inf = 0; inf < 4; inf++) {
                     weight = matricesWeightsData[matWeightIdx + inf];
                     if (weight > 0) {
-                        Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, matricesIndicesData[matWeightIdx + inf] * 16, weight, tempMatrix);
+                        Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, Math.floor(matricesIndicesData[matWeightIdx + inf] * 16), weight, tempMatrix);
                         finalMatrix.addToSelf(tempMatrix);
 
                     } else break;
@@ -3275,7 +3275,7 @@
                     for (inf = 0; inf < 4; inf++) {
                         weight = matricesWeightsExtraData![matWeightIdx + inf];
                         if (weight > 0) {
-                            Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, matricesIndicesExtraData![matWeightIdx + inf] * 16, weight, tempMatrix);
+                            Matrix.FromFloat32ArrayToRefScaled(skeletonMatrices, Math.floor(matricesIndicesExtraData![matWeightIdx + inf] * 16), weight, tempMatrix);
                             finalMatrix.addToSelf(tempMatrix);
 
                         } else break;