Continuous Collision Detection Incompatible with Kinematic Bodies?

Am I correct in thinking that continuous and continuous dynamic collision detection is not compatible with kinematic rigid bodies? I find that enabling CCD and CC for the dynamic and static collision meshes does not have any effect. The collisions go straight through, just as they do with discrete collisions. Just wanted to make sure that this is "by design" rather than "by chance".

 

The Continuous Dynamic collision setting only has an effect on non-kinematic rigidbodies. It is relevant for moving objects but not for stationary objects that they may come into contact with.

 

Yeah, I thought it was probably intentional, but it's a shame. If I let the physics engine take control of the bodies, slow moving objects gently embed themselves into objects. If I disable the physics engine and write my own physics, the collision engine can't keep up and fast moving objects go straight through objects. So it seems that - if I want to have fast moving objects at all, I need to write my own collision functions as well.

 

For anyone reading this who needs to enable "is kinematic" temporarily in an object with CCD, you can:

Code (CSharp):

1. rigBody.collisionDetectionMode = CollisionDetectionMode.Discrete; // you can use Speculative too
2. rigBody.isKinematic = true;
3. rigBody.detectCollisions = false;
4. // move your object as you want
5. rigBody.detectCollisions = true;
6. rigBody.isKinematic = false;
7. rigBody.collisionDetectionMode = CollisionDetectionMode.Continuous;

And it will work.
If you only enable and disable isKinematic on rigidbody with CCD, Unity will change its CollisionDetectionMode to Speculative. If this happens you can Debug.Log(rigBody.CollisioniDetectionMode) and it will tell you it is Continuous, but it's not true, it is Speculative, as you can check with ghost collisions and other behaviours.
This was tested with Unity 2018.3.6f1

Cheers