解决方案是使用ScissorStack。
@Override
public void draw(SpriteBatch batch, float parentAlpha) {
//Create a scissor recangle that covers my Actor.
Rectangle scissors = new Rectangle();
Rectangle clipBounds = new Rectangle(getX(),getY(),getWidth(),getHeight());
ScissorStack.calculateScissors(camera, batch.getTransformMatrix(), clipBounds, scissors);
batch.flush(); //Make sure nothing is clipped before we want it to.
ScissorStack.pushScissors(scissors);
//Draw the actor as usual
super.draw(batch, parentAlpha);
//Perform the actual clipping
ScissorStack.popScissors();
}