MeshCollider doesn't collide

Unity Engine
1

Hi there,

Im facing a strange problem with collisions:

first i’ve created 2 cubes, and then replaced the BoxColliders with MeshColliders and added a rigidbody on each cube.

i’ve also placed a suface with a BoxCollider under the cubes to be the “ground”.

Now I cant understand why the cubes don’t collide with each other… but with every other object (with BoxCollider or with a different mesh and a MeshCollider) the collisions occur correctly…

in short: 2 instances of the same object with MeshColliders and rigidbody aren’t colliding.

Anyone knows a way to fix it (make both cubes collide)?

2

Check this manual page under the Hints section:

“Mesh Colliders cannot collide with each other unless they are marked as Convex. Therefore, they are most useful for background objects like environment geometry.”

3

it does not make sense that much to use meshcolliders on players etc anyway because it will not animate. it will use the initial mesh data and remain like that

4

Don’t do that. Mesh colliders are only for static background geometry. (There is the convex option, but that has various limitations, such as being convex only, and still shouldn’t be used if you can feasibly use primitive colliders instead.)

–Eric

5

Thank you guys.

The cubes are only to illustrate… i will need to make physic interactions with more irregular meshes…

so, in this case the best sollution is to use many primitive colliders in the same object to achieve a more natural effect? like, 2 box colliders to a simple “h-shaped chair” ?

6

Yep.

–Eric