Hollow/inverse collider

[tacuna]

Use-case: (amongst things) constrain players(/entities) within a specific area (usually a box)

Expected behaviour: player collides with the area (interior) and cannot exit, i.e. pushed back (just like a regulator collider works but from inside to outside, instead of from outside to inside).

Alternatives

• Sensor, but this requires manually correcting the collisions (as i still want/need collisions), which is what Avian can, and should, do for me (if dynamic).
• Using a trimesh, but it has possible tunnelling issues as per documentation: Note that the resulting collider will be hollow and have no interior. This makes it more prone to tunnelling and other collision issues.
• Instead of using 1 (inverse) collider, e.g. for a box, use 6 (in 3D) regular box colliders to box in the player. Works but seems wasteful?
  • Good luck if you want a circle
  • This is how it is done in the move_marbles 2D example (although that makes sense as for that use case you also want a visual wall thickness anyway)

I have found the code has the concept of "solid" but it is specified per function (not per collider), and as far as i understand, not really indented for this use case?

Question: am i correct that this functionality is currently not support? If so, what is the suggested approach and is there a chance to support it in the future?