I can't get ANY simple collision to work!

I just started using unity recently and I have watched all the ‘getting started’ tutorials. My problem is, I simply can’t get ANYTHING to collide… I’m using Unity 3.4.2f3 on windows 7.

All I do is insert a simple plane object with [mesh collider], then a cube with a [box collider] and [rigid body]. I put the cube above the plane, hit play, and it falls right through.

In addition I have tried making the mesh collider convex, tried different combinations of colliders with one another (including convex mesh collider on both objects), tried making the plane static, etc… What in the world am I missing here?

I really want to learn this program, but if I can’t even figure this out… lol. I looked at all of the components attached to the objects in the tutorial video on cgcookie.com “Unity: Intro to User Interface Part 2” and everything seems to be identical, yet here I am… Somebody please help me!!! xD

edit: I tried applying [rigid body] to both objects and using different combinations of colliders with that as well (including checking and unchecking kinematic on both)… still has fallen through every time.

edit: Also, all the collision detection with the Bootcamp demo works just fine.

Never had such an issue. Make sure:

  • the objects arent parented to each other.
  • you didn’t set some strange settings in the collision matrix in the physics settings.
  • moving objects with rigidbody have either primitive collider(box, sphere, capsule) or a convex meshcollider
  • you don’t directly move the object “manually” by setting the transform.position.

Don’t use a plane with a mesh collider. Remove the mesh collider from it and add a box collider to it. I’ve had numerous issues with mesh collider collisions you should try use a box collider where possible.

Try increasing the size of the collider you are using