When using the ECS Physics Package, a ball rolling on a mesh will bounce or slow when passing over an edge within the mesh. I have previously asked Unity support about this issue and they said that it was a result of the collision detection method used in the new physics package. They went on to mention that this can be fixed by using ModifyNarrowPhaseContacts from https://github.com/Unity-Technologies/EntityComponentSystemSamples/blob/master/UnityPhysicsSamples/Assets/Demos/5.%20Modify/Scripts/ModifyNarrowphaseContactsBehaviour.cs However, this system only works in the case that friction is set to 0 and it also causes balls to not slow down when travelling up a sloped surface.
It was also suggested that I should try to use a single flat plane collider when possible but, at least in this case, that isn’t viable. Additionally, I would like to be able to roll the ball over curved or otherwise complex surfaces which wouldn’t really work with that idea.
Ideally there should be a way to stop balls from being affected like this by edges inside of a mesh. My guess is that I should be doing something to the contact data, something different than what’s in the ModifyNarrophaseContactsSystem but I don’t know what that should be.
This video shows the issue as best as I could record it. The ball is moving over a single (mostly) flat mesh which has been split up into many faces. Whenever it passes over an edge the ball jumps or is slowed. I should note that the ball is constrained by some invisible walls but this problem persists with those removed.
Unity Version: 2019.3.0.b7
Physics Package Version: 0.2.4
