May be off topic, but as PixelPalette said, this could bring a light on the matter:
Collision Filters are very useful for Physics games.
For example, I made a sideview ragdoll soccer prototype in Corona where every object had physics, but :
- ball had to collide with head, feet, and hand (fault!)
- the ball couldn't collide with the torso, legs
- all body parts were attached by joints, and should not collide with each other.
- the player's body parts had to collide with the obstacles, as well as the ball.
Without collision filters, this setup would be impossible!
Of course, this is an extreme example, but I think more and more people will request this as Construct gets more users and allows for more complex things.
developer.anscamobile.com/content/game-edition-collision-detection