Multiple Colliders, multiple Collision filters?

Unity Engine
,
1

I have an object with a child object, each has a PhysicsShape. The parent object has a PhysicsBody.

I would like, at runtime (i.e. after instantiating a clone of the converted entity) to set a collision filter on all the colliders. (in fact, at conversion time, I already define some specific belongs to / collides with values, and at runtime want to add a unique GroupIndex to each)

Somehow, only the parent entity has a PhysicsCollider. There seem to be sub-colliders, but I don’t understand how to get the ColliderKey that would be needed to access one.

Do I need to generate them as Force Unique?

Somehow the object seems to also not collide as expected (i.e. the belongs to / collides with values seem to get changed - isn’t having multiple filters on one entity possible?)

elaborateneargemsbuck
(illustration video, the collision filters are so the ship can launch missiles and projectiles from within its body / hull / shield colliders; the “mesh” on the shield is temporary because the convex hull generation usually stalls out)

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I suppose to solve the bullets problem, I can run disable the Broadphase pairs appropriately.

What would be interesting is, can I disable one of the colliders in a composite collider?

3

Ok, works like a charm with the Broadphase. I do need to sort out some physics issues post-collision event now. (not visible in video)

        [BurstCompile]
        private struct DisablePairsJob : IBodyPairsJob
        {
            [ReadOnly] public ComponentDataFromEntity<Owner> Owners;

            public unsafe void Execute(ref ModifiableBodyPair pair)
            {
                // Disable the pair if one owns the other
                var a = pair.Entities.EntityA;
                var b = pair.Entities.EntityB;

                if (Owners.Exists(a))
                {
                    if (Owners[a].entity == b) pair.Disable();
                }
                else if (Owners.Exists(b))
                {
                    if (Owners[b].entity == a) pair.Disable();
                }
            }
        }

grimfainthorseshoebat

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4

The “weird collision” problem was me accidentally not removing the static meshcollider off a quad I was converting and spawning :wink:

Works really great. Now to find out how to turn on and off colliders (like for the shield) efficiently. Probably also with the pairs job.

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