Clear blendshapes without memset

Avoids warning due to glm::vec3 not being trivially copyable

libraries/render-utils/src/Model.cpp

@@ -1949,7 +1949,9 @@ void Blender::run() {
         blendedMeshSizes.push_back(numVertsInMesh);
 
         // initialize offsets to zero
-        memset(unpackedBlendshapeOffsets.data(), 0, numVertsInMesh * sizeof(BlendshapeOffsetUnpacked));
+        for(BlendshapeOffsetUnpacked &bou : unpackedBlendshapeOffsets) {
+            bou.clear();
+        }
 
         // for each blendshape in this mesh, accumulate the offsets into unpackedBlendshapeOffsets.
         const float NORMAL_COEFFICIENT_SCALE = 0.01f;

libraries/shared/src/BlendshapeConstants.h

@@ -122,6 +122,25 @@ struct BlendshapeOffsetUnpacked {
     float positionOffsetX, positionOffsetY, positionOffsetZ;
     float normalOffsetX, normalOffsetY, normalOffsetZ;
     float tangentOffsetX, tangentOffsetY, tangentOffsetZ;
+
+    /**
+     * @brief Set all components of all the offsets to zero
+     *
+     * @note glm::vec3 is not trivially copyable, so it's not correct to clear it with memset.
+     */
+    void clear() {
+        positionOffsetX = 0.0f;
+        positionOffsetY = 0.0f;
+        positionOffsetZ = 0.0f;
+
+        normalOffsetX = 0.0f;
+        normalOffsetY = 0.0f;
+        normalOffsetZ = 0.0f;
+
+        tangentOffsetX = 0.0f;
+        tangentOffsetY = 0.0f;
+        tangentOffsetZ = 0.0f;
+    }
 };
 
 using BlendshapeOffset = BlendshapeOffsetPacked;