Unity ECS performance is very low when there are many physics collisions

[apkdev]

Looks like you’re creating a new collider every time you want to change the collision filter. (It’s a bit unfortunate that the collision filter is stored in the collider blob asset, hopefully this improves in the future.)

Instead of instantiating the colliders you can try forcing them to be unique so they’re baked separately:

@PhilSA

If I’m not mistaken, in the PhysicsShape component, you can enable “Force Unique” and that’ll make your colliders independent from each other.

Now you should be able to modify the collision filter directly without copying the blob asset:

@teasully

This seems to do the trick:

static void SetCollisionFilter(Entity entity, uint belongsTo, uint collidesWith)
{
  var collider = EntityManager.GetComponentData<PhysicsCollider>(entity);
  Assert.IsTrue(collider.Value.Value.CollisionType == CollisionType.Convex);

  unsafe
  {
    var header = (ConvexCollider*)collider.ColliderPtr;
    var filter = header->Filter;

    filter.BelongsTo = belongsTo;
    filter.CollidesWith = collidesWith;

    header->Filter = filter;
  }
}