Does a moving camera need a rigidbody attached?

Hello,

quick question : I understand that objects without a rigidbody attached are expected to be static by Unity. Moving such object will result in Unity having to recheck all the static geometry, something we want to avoid.

The camera in a scene is nothing more than a game object with a camera component attached to it. If my camera is going to move, does it mean I need to add a (possibly kinematic) rigidbody to it to avoid having all the static geometry being recalculated every time this camera moves?

 

colliders, not objects

camera doesn't usually have a collider attached.

 

What if I have a cube without a collider and I make it move? Does it matter at all that I add a rigidbody component?

 

http://docs.unity3d.com/Manual/CollidersOverview.html

whether or not a collider is static is based on a check box in the inspector, i.e. your choice, if you set a collider to static the game engine will make optimisations based on that.

If you then move a collider set to static, it needs to undo or fill in the gaps that those optimisations made, meaning overhead and relatively poor performance.


You can just not set a collider to static, it won't have the optimisations done to it, it can move happily by whatever method (rigidbody, direct position change through code, whatever).


Rigidbody is needed if you want to gameobject to be a part of the physics simulation, it doesn't have any affect on the above.

 

Not quite - in the case of colliders, they ARE considered to be static geometry by the physics engine if they do not have a rigidbody attached (the "Static" checkbox does not pertain to this).

If you have a gameobject with a collider attached but no rigidbody, and you move said collider around, it will incur a performance hit.

 

This issue was supposed to be fixed in 5.0. But I would benchmark it if you are concerned.