First off, thanks a lot for getting back to me, and for spending the time to investigate the issues I raised. Very much appreciated!
Also let me apologise for my statement about physics not working, it was in no way meant to sound harsh. I was a bit frustrated after having spent quite a lot of time trying again and again and getting pretty much nowhere.
Now, regarding your points,
Bear in mind that all I did there was to take the example referenced in documentation and change the physics engine from Ammo to Cannon.
Also, I see what you mean about impostors to be invisible and not seeing the point of contact between the two surfaces , but what I mean is more drastic than that.
If I take your working example and just change the camera angle https://playground.babylonjs.com/#66PS52#39 you will see that it really bounces off way before it gets in contact with the ground. That doesn’t happen with Ammo.
That’s a fair point, I will look it up and play around with it to grasp the difference with transform hierarchy.
True, but I am doing that before returning the scene. So I thought that once scene is returned the last value set in physicsRoot.position wins. Unless position values somehow cumulate (I will look into it) I am still confused about it.
I think I might understand what is going on there. It should have to do with when the physics calculation is executed and where the colliders in the ring and the ground happen to be in that moment. If I decrease gravity, using -1 instead of -10 as the Y component (so objects move slower between one frame and the other) then the ring never passes through. Also, as you said, the thickness of the colliders may have to do with that too.
With Cannon https://playground.babylonjs.com/#66PS52#40 the ring flips over once before touching the ground. I would not expect that!
That is actually something I noticed, and that I have no idea why it happens, sometimes with Cannon, objects in free fall seem to be affected by some torque (might be wrong) that should reasonably not be there…
That’s a great attitude. Fully appreciated and says a lot about the framework in general. Thank you!