Detecting a collision

I’m trying to create a kinematic entity (A) that can detect when another entity (B) is inside or intersecting with it. Like a trigger or sensor object, it doesn’t interact with the other (dynamic or kinematic) entity B, that should be detected, in any way.

So I use the ConfigureContactManifold callback to see if there is a collision. Just assuming that we have a collision inside that function yields collisions for objects that dont collide. I’ve tried to add a check wether they really collide:

var hasNonNegativeContact = false;
for (var i = 0; i < manifold.Count; i++)
{
    if (manifold.GetDepth(ref manifold, i) >= 0)
    {
        hasNonNegativeContact = true;
        break;
    }
}
if(hasNonNegativeContact)
{
    // we have collided
}

That works for simple stuff, but if the entity B uses a mesh collider that check doesn’t work.

I made two observations: 1: Sometimes there are more than 4 contacts and the contacts are “cleaned up” inside of unsafe void ChooseMostDistinct(NonconvexContactManifold* manifold, BufferPool pool) which reduces it to 4 contacts. In some cases it chooses the “wrong” contacts and only contacts with negative depth remain.

2: manifold.Count is 0 (Demo)

What would you recommend for filtering out non colliding entities?

[RossNordby]

Thanks for trying it; looks like there’s a subsequent issue that b7566c2aa0bfa0ecb6b878bdf64e0a59dce86664 should help with.

[Valdiralita]

Thanks for trying it; looks like there’s a subsequent issue that b7566c2 should help with.

I’ve tested the latest master (a5049c6cb06797a9bb3dfad9a6cb86775cf3f91b) and the issue is fixed! 🎉 Can’t wait for the next release on nuget 😉