public void addChildShape(CollisionShape shape, Vector3f location, Matrix3f rotation) {
        if(shape instanceof CompoundCollisionShape){
            throw new IllegalStateException("CompoundCollisionShapes cannot have CompoundCollisionShapes as children!");
        }
        Transform transA = new Transform(Converter.convert(rotation));
        Converter.convert(location, transA.origin);
        Converter.convert(rotation, transA.basis);
        children.add(new ChildCollisionShape(location.clone(), rotation.clone(), shape));
        ((CompoundShape) cShape).addChildShape(transA, shape.getCShape());
    }
adds a child shape at the given local translation
@param shape the child shape to add
@param location the local location of the child shape
@param rotation the local orientation of the child shape (not null,
unaffected)
jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/CompoundCollisionShape.java