Best way to tear apart a piece of paper?

Questions & Answers
1

Remember the game at the carnival that allowed to you shoot a bb gun at a target with the red star and if you removed the entire red star from the paper target you won a prize?

I'm working on that game.. major stumbling block for me.. how do you tear apart the paper?

I have a couple of ideas, but neither really seems that good. 1) pre-tear up the paper and piece it together and allow them to take it apart - seems to static, not random enough 2) where the bb's hit, make a black dot on the paper (really thin cube primitive likely) - not realistic or that fun since the paper wouldn't tear..

Any other ideas?

2

Make the paper out of many triangles, where the bullet hits fade out the alpha on those verts so that you can see through the paper, instantiate paper tear models around the hole.

Then when the 2nd shot is fired check if it is next to a previous hole and then join them up to make a bigger hole so you don't end up with loads of tear models floating about.

You can use raycast to return which triangle was hit:

http://unity3d.com/support/documentation/ScriptReference/RaycastHit-triangleIndex.html