@Override
    protected Matrix4f getTransformMatrix(Geometry g){
        // Compute the Local matrix for the geometry
        cachedLocalMat.loadIdentity();
        cachedLocalMat.setRotationQuaternion(g.localTransform.getRotation());
        cachedLocalMat.setTranslation(g.localTransform.getTranslation());

        TempVars vars = TempVars.get();
        Matrix4f scaleMat = vars.tempMat4;
        scaleMat.loadIdentity();
        scaleMat.scale(g.localTransform.getScale());
        cachedLocalMat.multLocal(scaleMat);
        vars.release();
        return cachedLocalMat;
    }
SimpleBatchNode  comes with some restrictions, but can yield better performances.
Geometries to be batched has to be attached directly to the BatchNode
You can't attach a Node to a SimpleBatchNode
SimpleBatchNode is recommended when you have a large number of geometries using the 
same material that does not require a complex scene graph structure.

@see BatchNode
@author Nehon
jme3-core/src/main/java/com/jme3/scene/SimpleBatchNode.java