谢谢你的建议。如果你想使用减法mask（反剪），建议在运行时进行。例如，spine-unity运行时支持Unity sprite masks:
Blog: Unity SpriteMask and RectMask2D support
Thank you for your suggestion. If you want to do subtraction masking(inverse clipping), it is recommended to do it at runtime. For example, the spine-unity runtime supports Unity sprite masks:
Blog: Unity SpriteMask and RectMask2D support
