- fbx: permit empty deformers.

code/FBXConverter.cpp

@@ -622,6 +622,10 @@ private:
 				const WeightIndexArray& indices = cluster->GetIndices();
 				const WeightArray& weights = cluster->GetWeights();
 
+				if(indices.empty()) {
+					continue;
+				}
+
 				const MatIndexArray& mats = geo.GetMaterialIndices();
 
 				bool ok = false;		

code/FBXDeformer.cpp

@@ -82,23 +82,27 @@ Cluster::Cluster(uint64_t id, const Element& element, const Document& doc, const
 {
 	const Scope& sc = GetRequiredScope(element);
 
-	const Element& Indexes = GetRequiredElement(sc,"Indexes",&element);
-	const Element& Weights = GetRequiredElement(sc,"Weights",&element);
+	const Element* const Indexes = sc["Indexes"];
+	const Element* const Weights = sc["Weights"];
+
 	const Element& Transform = GetRequiredElement(sc,"Transform",&element);
 	const Element& TransformLink = GetRequiredElement(sc,"TransformLink",&element);
 
 	transform = ReadMatrix(Transform);
 	transformLink = ReadMatrix(TransformLink);
 
-	ReadVectorDataArray(indices,Indexes);
-	ReadVectorDataArray(weights,Weights);
+	// it is actually possible that there be Deformer's with no weights
+	if (!!Indexes != !!Weights) {
+		DOMError("either Indexes or Weights are missing from Cluster",&element);
+	}
 
-	if(indices.size() != weights.size()) {
-		DOMError("sizes of index and weight array don't match up",&element);
+	if(Indexes) {
+		ReadVectorDataArray(indices,*Indexes);
+		ReadVectorDataArray(weights,*Weights);
 	}
 
-	if(!indices.size()) {
-		DOMWarning("encountered empty deformer",&element);
+	if(indices.size() != weights.size()) {
+		DOMError("sizes of index and weight array don't match up",&element);
 	}
 
 	// read assigned node

code/FBXDocument.h

@@ -739,13 +739,16 @@ public:
 
 public:
 
-	/** get the list of deformer weights associated with this cluster */
+	/** get the list of deformer weights associated with this cluster.
+	 *  Use #GetIndices() to get the associated vertices. Both arrays
+	 *  have the same size (and may also be empty). */
 	const WeightArray& GetWeights() const {
 		return weights;
 	}
 
 	/** get indices into the vertex data of the geometry associated
-	 *  with this cluster.*/
+	 *  with this cluster. Use #GetWeights() to get the associated weights.
+	 *  Both arrays have the same size (and may also be empty). */
 	const WeightIndexArray& GetIndices() const {
 		return indices;
 	}