Quick question on Rigidbody/Colliders

Unity Engine
1

The answer occurred to me already, but I would like someone whos actually knows the correct answer.

So lets say I have a tank. It has several colliders. Combination of Mesh/Sphere. Currently the sphere colliders are on the wheels. The wheels have a script on them. The wheel scripts dont seem to get Collision events.

Now I assume this is because they dont have individual rigidbody’s attached to them? The parent transform does.

I havnt tested this out (it only just occured to me now), but i’m assuming all the collision events are being swallowed by the transform with the rigidbody on them? Can someone confirm this is the way it works?

If thats the case what is the downside of putting more rigidbodies into an object… should I be concerned with how many rigidbodies I use on an object? I was orgininally aiming at iOS, but have decided to make this game PC, so I assume the skys the limit. Would be nice to keep it as low as possible though!

2

Of course you should be concerned with the number of rigidbodies in your scene. That being said, several more to support your wheels may not be a huge issue.

The reason you are not recieving collisions is that one body in an collision needs to be a rigidbody, so, what not make what you want to trigger a collision with your tires, say a projectile? Another tanks armour? Have a rigidbody?

Just a suggestion.