I understand that a simple sphere collider in Unity is a raycast in all directions with a certain length. How many Raycast events does a sphere collider trigger? At what degree increments are the rays cast?
Not always a raycast. Unity3D's collision is based on PhysX and it support multiple types of geometry queries:
- raycasts test a ray against a geometry object.
- sweeps move one geometry object along a line to find the first point of intersection with another geometry object.
- overlaps determine whether two geometry objects intersect.
How unity technologies implements every one of them is not exposed as far as i know.