Thank you for the reply, it was very helpful!

I've managed to use Unity SpriteMask with Spine objects but I've encountered another problem. It seems that when a sprite is clipped by mask (it uses material with shader that is capable of being clipped) it looses ability to receive shadows. We are trying to achieve effect of a 'photo' that consist of few sprites / Spine objects. All those objects must fit inside photo frame (that's why we're using sprite mask). We also want this photo to cast and receive shadows, but unfortunately receiving shadows does't work when object is clipped. I've tried different shaders and it seems like shaders that can be clipped by SpriteMask don't have ability to receive shadows. Is there any way to achieve described effect ? I'll attach image that hopefully will help to understand my problem.

Hello,
Recently I've encountered a problem. While Unity sprite mask is clipping sprites perfectly I cannot make it work with Spine objects. Do you know any way to clip Spine object using another sprite's bounds by any chance? I'd prefer not to use any shaders for that as we want to use custom shaders for special visual effects for Spine objects. It's also worth noticing that Unity UI clipping maks works perfectly with Spine skeleton graphic objects, but we need it to work with skeleton animation (interact with it's mesh renderer).