Question by MadJohny · Jul 30, 2014 at 08:06 AM · raycast collider linecast capsulecollider spherecollider

Raycast, Linecast, sphere collider or capsule collider?

Just wondering what is faster/more reliable? I know that the sphere collider is faster than the capsule collider, what about raycasts vs linecasts? And also one of the casts vs one of the colliders? I plan on using this in a real-time bullet system like the ones seen in the STALKER series, but I would like to know which of these is more reliable, I heard that particles use super fast sphere collisions instead of raycasts (I think they said it in the microstar demo thing), does that mean that collisions > raycasts?

Thanks in advance.

Add comment · Show 2

robertbu · Jul 30, 2014 at 04:08 PM 0

I suggest you run the test yourself. In 30 to 60 minutes you could have your answer. If I was around my desktop, I might run the test out of curiosity.

Add a number of widely spaced objects to the scene.
Add an FPS script to the scene.
Create a script that does one type of cast repeatedly in a single frame. Do a GUI.Label or GUIText that reports the number of iterations. Add a key that increases the number iterations per frame.
Do a build. Building for your target platform is best, but any build is better than running the test in the editor. The results in the editor often don't reflect runtime results.
Run the app and increase the iterations until you see an FPS slowdown. Keep increasing until the FPS becomes unusable.
Repeat with the different kinds of raycasts.

I expect that linecasts and raycasts of similar distance will be comparable. Don't know your application for this information, but keep in mind Collider.Raycast(). Raycasting against a single collider is usually far more efficient that raycasting against the scene. Also for complete results, you may want to test other factors like the complexity of meshes used in the test.