Determine that an object is -within- a trigger

Questions & Answers
1

Let's say I have an oddly shaped MeshCollider set up as a trigger, and I want to check if a certain object is within this trigger.

Unfortunately, OnTriggerStay is only called if the object touched the boundaries of the trigger, and I found OnTriggerEnter and OnTriggerExit rather unreliable to tell which objects went in and which went out.

Any bright ideas?

2

Haven't tried this, but the following algorithm from computational geometry should work:

http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html#Polyhedron

Basically, you fire a ray from a point, and if that ray hits an odd number of faces of the mesh, then you are inside. Use RaycastAll to get back all the hits, not just the first one, and use the new raycast layers feature to avoid hitting other meshes.