Warp ball

How do I...?
1

In gravicannon there will be warp ball, that needs to be physics object (it’s affected by gravity of planets), but will not collide with objects other than diamonds/coins rubies) However in physics extension there seems to be only one “collision group” so warp balls will collide with planets (they’re not supposed to). I need them to collide only with rubies/diamonds/coins, but still be affected by gravity by other nearby planets.

Planets and black holes are physics objects, so they can collide with balls (true, I could use pixel-perfect collision from Sprite object, but it wouldn’t work for Bouncing balls that have restitution applied). How to achieve that?

2

Bump. Need help here.

3

Anyone has an idea here? Because I have now almost all basic game mechanics except warp ball and few minor tweaks.

4

You can cheat a little.
Keep your planet sprites, but use a 1pixel-large invisible sprite to generate gravity for each one.
If your warp-ball is too close, make it disappear or send the warp-ball a little off, to avoid collision.
You could also desactivate its physics, the time for the warp-ball to pass through him, and activate it again.