Using trigger is slower than collision? why?

Questions & Answers
1

I have a few hundred spheres with collider on screen. When I checked the box “is trigger”, framerate slows down a lot.

I would think OnCollisionEnter() and OnTriggerEnter() is very similar, why using trigger(i.e.OnTriggerEnter()) is slower than using collision(i.e.OnCollisionEnter()) so much?

2

tough to say without more info. here are some guesses. triggers can collide with more types of colliders, see the collision action matrix for details here: http://unity3d.com/support/documentation/Components/class-BoxCollider.html. Perhaps the code inside of the called function is different? For instance including the argument of Collider other will result in extra processing.