context.enforceState(_tranparentCull);
context.enforceState(_transparentZBuff);
// first render back-facing tris only
_tranparentCull.setCullFace(CullState.Face.Front);
mesh.draw(renderer);
// revert z state
context.clearEnforcedState(StateType.ZBuffer);
if (oldZState != null) {
context.enforceState(oldZState);