Box collider vs Quad(mesh) collider

Questions & Answers
1

hey guys.
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I keep reading that mesh colliders are inefficient, but I’m not sure if that’s just because most meshes are more complex or something else.
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remember that the quad is divided into just two triangles.
so in case i need a surface to block some objects, is it more efficient(in performance) to use a quad(mesh collider), or a box collider? or a box collider with 0 in x size?
I only need to detect collisions from one side.
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thanks in advance.

2

I was very curious to find this answer, so instead of reading up things here an there I decided to put this into practice.

I made a scene in Unity where a Quad spawns every 0.3 seconds.
10 units below the spawn I put a Plane to cause an interaction between the two objects.

(All testing was done in the Unity Editor and obviously this is was not a definitive test)

Test 1

First I tried the Quad with the Mesh Collider and I was getting around 1,000 frames per second.

Test 2

Then I tested with the Quad with the Box Collider and to my utter surprise, I was getting between 4,000-10,000 frames per second.

Test 3

Then I made the depth of the Box Collider to 0 and Quads started falling through. So I changed the Plane’s collider to a Box Collider and the Quads stopped falling through till the time they were upright. As soon as they would lay flat they would go through. Still, I was getting between 4,000 and 10,000 frames per second.

I think since a cube is a primitive Unity has added optimization for the Box Collider.

I was very surprised by the results.

But in actual practice, it wouldn’t matter too much unless you have thousands of objects using a collider. So use whichever collider worry free!