Bugfix: NPE was raised when the object had no material.

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@8099 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/blender/com/jme3/scene/plugins/blender/meshes/MeshHelper.java

@@ -406,7 +406,7 @@ public class MeshHelper extends AbstractBlenderHelper {
 			}
 			for(Entry<Material, List<Geometry>> entry : materialMap.entrySet()) {
 				MaterialContext materialContext = dataRepository.getMaterialContext(entry.getKey());
-				if(materialContext.getTexturesCount()>0) {
+				if(materialContext != null && materialContext.getTexturesCount()>0) {
 					UVCoordinatesGenerator.generateUVCoordinates(materialContext.getUvCoordinatesType(), 
 							materialContext.getProjectionType(),
 							materialContext.getTextureDimension(), entry.getValue());