Bugfix: fixed artifacts that were caused by adding bones with no weight

to bone index buffer.

jme3-blender/src/main/java/com/jme3/scene/plugins/blender/meshes/TemporalMesh.java

@@ -518,9 +518,15 @@ public class TemporalMesh extends Geometry {
                         Map<String, Float> vertexGroupsForVertex = vertexGroups.get(vertIndex);
                         for (Entry<String, Integer> entry : boneIndexes.entrySet()) {
                             if (vertexGroupsForVertex.containsKey(entry.getKey())) {
-                                boneBuffersForVertex.put(vertexGroupsForVertex.get(entry.getKey()), entry.getValue());
+                                float weight = vertexGroupsForVertex.get(entry.getKey());
+                                if(weight > 0) {// no need to use such weights
+                                    boneBuffersForVertex.put(weight, entry.getValue());
                                 }
                             }
+                        }
+                        if(boneBuffersForVertex.size() == 0) {// attach the vertex to zero-indexed bone so that it does not collapse to (0, 0, 0)
+                            boneBuffersForVertex.put(1.0f, 0);
+                        }
                         boneBuffers.add(boneBuffersForVertex);
                     }
                 }

jme3-blender/src/main/java/com/jme3/scene/plugins/blender/modifiers/ArmatureModifier.java

@@ -53,8 +53,8 @@ import com.jme3.scene.plugins.blender.meshes.TemporalMesh;
                 modifying = useBoneEnvelopes || useVertexGroups;
                 if (modifying) {// if neither option is used the modifier will not modify anything anyway
                     Structure armatureObject = pArmatureObject.fetchData().get(0);
-                    
-                    // load skeleton
+                    if(blenderContext.getSkeleton(armatureObject.getOldMemoryAddress()) == null) {
+                        LOGGER.fine("Creating new skeleton for armature modifier.");
                         Structure armatureStructure = ((Pointer) armatureObject.getFieldValue("data")).fetchData().get(0);
                         List<Structure> bonebase = ((Structure) armatureStructure.getFieldValue("bonebase")).evaluateListBase();
                         List<Bone> bonesList = new ArrayList<Bone>();
@@ -65,6 +65,9 @@ import com.jme3.scene.plugins.blender.meshes.TemporalMesh;
                         Bone[] bones = bonesList.toArray(new Bone[bonesList.size()]);
                         skeleton = new Skeleton(bones);
                         blenderContext.setSkeleton(armatureObject.getOldMemoryAddress(), skeleton);
+                    } else {
+                        skeleton = blenderContext.getSkeleton(armatureObject.getOldMemoryAddress());
+                    }                    
                 }
             } else {
                 modifying = false;