SImple fix to the case of multiple material in a mesh with different opacity

libraries/fbx/src/FBXReader.cpp

@@ -976,6 +976,8 @@ ExtractedMesh extractMesh(const FBXNode& object, unsigned int& meshIndex) {
     data.extracted.mesh.meshIndex = meshIndex++;
     QVector<int> materials;
     QVector<int> textures;
+    bool isMaterialPerPolygon = false;
+
     foreach (const FBXNode& child, object.children) {
         if (child.name == "Vertices") {
             data.vertices = createVec3Vector(getDoubleVector(child));
@@ -1105,8 +1107,19 @@ ExtractedMesh extractMesh(const FBXNode& object, unsigned int& meshIndex) {
             foreach (const FBXNode& subdata, child.children) {
                 if (subdata.name == "Materials") {
                     materials = getIntVector(subdata);
+                    if (materials.size() > 1) {
+                        
+                    }
+                } else if (subdata.name == "MappingInformationType") {
+                    if (subdata.properties.at(0) == "ByPolygon") {   
+                        isMaterialPerPolygon = true;
+                    } else {
+                        isMaterialPerPolygon = false;
+                    }
                 }
             }
+
+
         } else if (child.name == "LayerElementTexture") {
             foreach (const FBXNode& subdata, child.children) {
                 if (subdata.name == "TextureId") {
@@ -1116,6 +1129,12 @@ ExtractedMesh extractMesh(const FBXNode& object, unsigned int& meshIndex) {
         }
     }
 
+
+    bool isMultiMaterial = false;
+    if (isMaterialPerPolygon) {
+        isMultiMaterial = true;
+    }
+
     // convert the polygons to quads and triangles
     int polygonIndex = 0;
     QHash<QPair<int, int>, int> materialTextureParts;
@@ -2104,6 +2123,9 @@ FBXGeometry extractFBXGeometry(const FBXNode& node, const QVariantHash& mapping,
                         if (type.contains("diffuse")) {
                             diffuseTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
 
+                        } else if (type.contains("transparentcolor")) { // it should be TransparentColor...
+                            // THis is how Maya assign a texture that affect diffuse color AND transparency ? 
+                            diffuseTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
                         } else if (type.contains("bump") || type.contains("normal")) {
                             bumpTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
                         

libraries/render-utils/src/GeometryCache.cpp

@@ -2239,10 +2239,17 @@ bool NetworkMeshPart::isTranslucent() const {
     return diffuseTexture && diffuseTexture->isTranslucent();
 }
 
+
+bool NetworkMesh::isPartTranslucent(const FBXMesh& fbxMesh, int partIndex) const {
+    assert(partIndex >= 0);
+    assert(partIndex < parts.size());
+    return (parts.at(partIndex).isTranslucent() || fbxMesh.parts.at(partIndex).opacity != 1.0f);
+}
+
 int NetworkMesh::getTranslucentPartCount(const FBXMesh& fbxMesh) const {
     int count = 0;
     for (int i = 0; i < parts.size(); i++) {
-        if (parts.at(i).isTranslucent() || fbxMesh.parts.at(i).opacity != 1.0f) {
+        if (isPartTranslucent(fbxMesh, i)) {
             count++;
         }
     }

libraries/render-utils/src/GeometryCache.h

@@ -398,6 +398,7 @@ public:
     QVector<NetworkMeshPart> parts;
     
     int getTranslucentPartCount(const FBXMesh& fbxMesh) const;
+    bool isPartTranslucent(const FBXMesh& fbxMesh, int partIndex) const;
 };
 
 #endif // hifi_GeometryCache_h

libraries/render-utils/src/Model.cpp

@@ -1827,12 +1827,18 @@ void Model::segregateMeshGroups() {
         // Debug...
         int totalParts = mesh.parts.size();
         for (int partIndex = 0; partIndex < totalParts; partIndex++) {
-            // this is a good place to create our renderPayloads
+            if (networkMesh.isPartTranslucent(mesh, partIndex)) {
-            if (translucentMesh) {
                 _transparentRenderItems << std::make_shared<MeshPartPayload>(true, this, i, partIndex);
             } else {
                 _opaqueRenderItems << std::make_shared<MeshPartPayload>(false, this, i, partIndex);
             }
+
+            // this is a good place to create our renderPayloads
+        /*    if (translucentMesh) {
+                _transparentRenderItems << std::make_shared<MeshPartPayload>(true, this, i, partIndex);
+            } else {
+                _opaqueRenderItems << std::make_shared<MeshPartPayload>(false, this, i, partIndex);
+            }*/
         }
     }
     _meshGroupsKnown = true;