Bugfix: fixed a bug that caused NPE during vertex groups loading when

mesh block was saved without its parent.

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

@@ -286,30 +286,33 @@ public class MeshHelper extends AbstractBlenderHelper {
         List<Map<String, Float>> result = new ArrayList<Map<String, Float>>();
 
         Structure parent = blenderContext.peekParent();
-        Structure defbase = (Structure) parent.getFieldValue("defbase");
-        List<String> groupNames = new ArrayList<String>();
-        List<Structure> defs = defbase.evaluateListBase();
-        for (Structure def : defs) {
-            groupNames.add(def.getFieldValue("name").toString());
-        }
+        if(parent != null) {
+        	// the mesh might be saved without its parent (it is then unused)
+        	Structure defbase = (Structure) parent.getFieldValue("defbase");
+            List<String> groupNames = new ArrayList<String>();
+            List<Structure> defs = defbase.evaluateListBase();
+            for (Structure def : defs) {
+                groupNames.add(def.getFieldValue("name").toString());
+            }
 
-        Pointer pDvert = (Pointer) meshStructure.getFieldValue("dvert");// dvert = DeformVERTices
-        if (pDvert.isNotNull()) {// assigning weights and bone indices
-            List<Structure> dverts = pDvert.fetchData();
-            for (Structure dvert : dverts) {
-                Map<String, Float> weightsForVertex = new HashMap<String, Float>();
-                Pointer pDW = (Pointer) dvert.getFieldValue("dw");
-                if (pDW.isNotNull()) {
-                    List<Structure> dw = pDW.fetchData();
-                    for (Structure deformWeight : dw) {
-                        int groupIndex = ((Number) deformWeight.getFieldValue("def_nr")).intValue();
-                        float weight = ((Number) deformWeight.getFieldValue("weight")).floatValue();
-                        String groupName = groupNames.get(groupIndex);
+            Pointer pDvert = (Pointer) meshStructure.getFieldValue("dvert");// dvert = DeformVERTices
+            if (pDvert.isNotNull()) {// assigning weights and bone indices
+                List<Structure> dverts = pDvert.fetchData();
+                for (Structure dvert : dverts) {
+                    Map<String, Float> weightsForVertex = new HashMap<String, Float>();
+                    Pointer pDW = (Pointer) dvert.getFieldValue("dw");
+                    if (pDW.isNotNull()) {
+                        List<Structure> dw = pDW.fetchData();
+                        for (Structure deformWeight : dw) {
+                            int groupIndex = ((Number) deformWeight.getFieldValue("def_nr")).intValue();
+                            float weight = ((Number) deformWeight.getFieldValue("weight")).floatValue();
+                            String groupName = groupNames.get(groupIndex);
 
-                        weightsForVertex.put(groupName, weight);
+                            weightsForVertex.put(groupName, weight);
+                        }
                     }
+                    result.add(weightsForVertex);
                 }
-                result.add(weightsForVertex);
             }
         }
         return result;