fix handling of normals. don't crash when extracting a mesh from a polyvox with no 'on' voxels

libraries/entities-renderer/src/RenderablePolyVoxEntityItem.h

@@ -61,6 +61,8 @@ public:
     virtual uint8_t getVoxel(int x, int y, int z) override;
     virtual bool setVoxel(int x, int y, int z, uint8_t toValue) override;
 
+    int getOnCount() const override { return _onCount; }
+
     void render(RenderArgs* args) override;
     virtual bool supportsDetailedRayIntersection() const override { return true; }
     virtual bool findDetailedRayIntersection(const glm::vec3& origin, const glm::vec3& direction,

libraries/entities/src/EntityScriptingInterface.cpp

@@ -930,11 +930,15 @@ bool EntityScriptingInterface::setVoxelsInCuboid(QUuid entityID, const glm::vec3
 void EntityScriptingInterface::voxelsToMesh(QUuid entityID, QScriptValue callback) {
     PROFILE_RANGE(script_entities, __FUNCTION__);
 
-    bool success;
+    bool success { false };
-    QScriptValue mesh;
+    QScriptValue mesh { false };
 
     polyVoxWorker(entityID, [&](PolyVoxEntityItem& polyVoxEntity) mutable {
-        success = polyVoxEntity.getMeshAsScriptValue(callback.engine(), mesh);
+        if (polyVoxEntity.getOnCount() == 0) {
+            success = true;
+        } else {
+            success = polyVoxEntity.getMeshAsScriptValue(callback.engine(), mesh);
+        }
         return true;
     });
 

libraries/entities/src/PolyVoxEntityItem.h

@@ -57,6 +57,8 @@ class PolyVoxEntityItem : public EntityItem {
     virtual void setVoxelData(QByteArray voxelData);
     virtual const QByteArray getVoxelData() const;
 
+    virtual int getOnCount() const { return 0; }
+
     enum PolyVoxSurfaceStyle {
         SURFACE_MARCHING_CUBES,
         SURFACE_CUBIC,

libraries/model/src/model/Geometry.cpp

@@ -138,15 +138,13 @@ Box Mesh::evalPartsBound(int partStart, int partEnd) const {
 model::MeshPointer Mesh::map(std::function<glm::vec3(glm::vec3)> vertexFunc,
                              std::function<glm::vec3(glm::vec3)> normalFunc,
                              std::function<uint32_t(uint32_t)> indexFunc) {
-    int attributeTypeNormal = gpu::Stream::InputSlot::NORMAL; // libraries/gpu/src/gpu/Stream.h
-
     // vertex data
-    gpu::Resource::Size vertexSize = getNumVertices() * sizeof(glm::vec3);
-    unsigned char* resultVertexData  = new unsigned char[vertexSize];
-    unsigned char* vertexDataCursor = resultVertexData;
-
     const gpu::BufferView& vertexBufferView = getVertexBuffer();
     gpu::BufferView::Index numVertices = (gpu::BufferView::Index)getNumVertices();
+    gpu::Resource::Size vertexSize = numVertices * sizeof(glm::vec3);
+    unsigned char* resultVertexData = new unsigned char[vertexSize];
+    unsigned char* vertexDataCursor = resultVertexData;
+
     for (gpu::BufferView::Index i = 0; i < numVertices; i ++) {
         glm::vec3 pos = vertexFunc(vertexBufferView.get<glm::vec3>(i));
         memcpy(vertexDataCursor, &pos, sizeof(pos));
@@ -154,12 +152,13 @@ model::MeshPointer Mesh::map(std::function<glm::vec3(glm::vec3)> vertexFunc,
     }
 
     // normal data
-    gpu::Resource::Size normalSize = getNumAttributes() * sizeof(glm::vec3);
+    int attributeTypeNormal = gpu::Stream::InputSlot::NORMAL; // libraries/gpu/src/gpu/Stream.h
-    unsigned char* resultNormalData  = new unsigned char[normalSize];
+    const gpu::BufferView& normalsBufferView = getAttributeBuffer(attributeTypeNormal);
+    gpu::BufferView::Index numNormals = (gpu::BufferView::Index)normalsBufferView.getNumElements();
+    gpu::Resource::Size normalSize = numNormals * sizeof(glm::vec3);
+    unsigned char* resultNormalData = new unsigned char[normalSize];
     unsigned char* normalDataCursor = resultNormalData;
 
-    const gpu::BufferView& normalsBufferView = getAttributeBuffer(attributeTypeNormal);
-    gpu::BufferView::Index numNormals =  (gpu::BufferView::Index)getNumAttributes();
     for (gpu::BufferView::Index i = 0; i < numNormals; i ++) {
         glm::vec3 normal = normalFunc(normalsBufferView.get<glm::vec3>(i));
         memcpy(normalDataCursor, &normal, sizeof(normal));
@@ -168,12 +167,12 @@ model::MeshPointer Mesh::map(std::function<glm::vec3(glm::vec3)> vertexFunc,
     // TODO -- other attributes
 
     // face data
-    gpu::Resource::Size indexSize = getNumIndices() * sizeof(uint32_t);
+    const gpu::BufferView& indexBufferView = getIndexBuffer();
-    unsigned char* resultIndexData  = new unsigned char[indexSize];
+    gpu::BufferView::Index numIndexes = (gpu::BufferView::Index)getNumIndices();
+    gpu::Resource::Size indexSize = numIndexes * sizeof(uint32_t);
+    unsigned char* resultIndexData = new unsigned char[indexSize];
     unsigned char* indexDataCursor = resultIndexData;
 
-    const gpu::BufferView& indexBufferView = getIndexBuffer();
-    gpu::BufferView::Index numIndexes =  (gpu::BufferView::Index)getNumIndices();
     for (gpu::BufferView::Index i = 0; i < numIndexes; i ++) {
         uint32_t index = indexFunc(indexBufferView.get<uint32_t>(i));
         memcpy(indexDataCursor, &index, sizeof(index));
@@ -229,7 +228,7 @@ void Mesh::forEach(std::function<void(glm::vec3)> vertexFunc,
 
     // normal data
     const gpu::BufferView& normalsBufferView = getAttributeBuffer(attributeTypeNormal);
-    gpu::BufferView::Index numNormals =  (gpu::BufferView::Index)getNumAttributes();
+    gpu::BufferView::Index numNormals =  (gpu::BufferView::Index) normalsBufferView.getNumElements();
     for (gpu::BufferView::Index i = 0; i < numNormals; i ++) {
         normalFunc(normalsBufferView.get<glm::vec3>(i));
     }
@@ -237,7 +236,7 @@ void Mesh::forEach(std::function<void(glm::vec3)> vertexFunc,
 
     // face data
     const gpu::BufferView& indexBufferView = getIndexBuffer();
-    gpu::BufferView::Index numIndexes =  (gpu::BufferView::Index)getNumIndices();
+    gpu::BufferView::Index numIndexes = (gpu::BufferView::Index)getNumIndices();
     for (gpu::BufferView::Index i = 0; i < numIndexes; i ++) {
         indexFunc(indexBufferView.get<uint32_t>(i));
     }

libraries/script-engine/src/ModelScriptingInterface.cpp

@@ -61,7 +61,12 @@ QScriptValue ModelScriptingInterface::appendMeshes(MeshProxyList in) {
     foreach (const MeshProxy* meshProxy, in) {
         MeshPointer mesh = meshProxy->getMeshPointer();
         totalVertexCount += mesh->getNumVertices();
-        totalAttributeCount += mesh->getNumAttributes();
+
+        int attributeTypeNormal = gpu::Stream::InputSlot::NORMAL; // libraries/gpu/src/gpu/Stream.h
+        const gpu::BufferView& normalsBufferView = mesh->getAttributeBuffer(attributeTypeNormal);
+        gpu::BufferView::Index numNormals = (gpu::BufferView::Index)normalsBufferView.getNumElements();
+        totalAttributeCount += numNormals;
+
         totalIndexCount += mesh->getNumIndices();
     }