How would I go about breaking a mesh up where a plane intersects it? The ultimate goal would be to allow someone to do something like carving a branch. I've seen example in the procedural.zip on unity about sculpting but it looks like you can only add to the mesh with their script via adding vertexes.
Many 3d authoring applications support some shape or form of this. Some refer to the technique of creating shapes by carving them with other shapes as a "Boolean Operation". There's a nice acedemic term for this, but I can't seem to remember it right now.
Nothing is stopping you from programming this in Unity, however it's pretty heavy on math, so you'd probably not want to start without a cup of coffee on your desk.
answered Jan 15 '10 at 12:21 PM
Lucas Meijer 1 ♦♦
Have you looked into creating a mesh with lots of vertices and then altering the mesh?
You'll need to do a camera.ScreenPointToRay() to find which triangle you are clicking on, then using the triangle you can find it's 3 points and then alter the mesh accordingly.
You'd need to compensate for the rotation of the object etc.
Example from Unity Reference Manual
answered Jan 12 '10 at 03:44 AM