Newbie Collider Queries.

Questions & Answers
1

I'm a 3D artist mainly, and I imported two models into unity from blender using 2.49, as 2.5 fbx exporter doesn't seem to work, just for a test. One was a wall model, very basic, about 64 triangles and untextured. I clicked on generate colliders for it but no collision detection happens, I can move straight through it.

Do I then have to create unity prefabs and set them as invisible, and then make colliders for those objects?

Also, multiple collider objects, such as a character model or spaceship or some such, I can't seem to simply attach multiple colliders to a parent object, in this case the model itself, just the one.

So, I suppose the same again, is it simply a matter of creating multiple cubes/spheres etc, setting them to invisible, attaching colliders to them and resizing as necessary?

And will the extra invisible geometry impact on the frame rate?

Thank you.

2

That's a lot of questions for one post...

Blender has problems being imported into unity, you can try using other export file types, 3DS works for me.

When generating mesh colliders you should know that mesh colliders wont collide with each other unless one of them is set to convex = true. You can do this in the inspector. For a fast moving game you're better off with unity primitive colliders any way as they're faster and more accurate.

You should only ever have one kind of collider on a game object, what you need to do is create more empty game objects and attach colliders to them and then attach the game object as a child to the main object. You can use multiple colliders to approximate the shape of your model.

Colliders with no mesh renderer wont impact the game speed noticeably, go nuts.