Mackey… have you found ANY AmmoJS demos/examples that use these parameters? (both on rigids and softs).
It’s likely that OIMO belongsTo (a grouping thing) and collidesWith (a masking-by-group thing) are parallels to those two Ammo params you speak-of.
In Oimo, which is just like Ammo only spelt different (not)… I needed to add belongsTo and collidesWith to a custom Oimo impostor and custom Oimo plugin. https://www.babylonjs-playground.com/#1ND6TH#194
Control-F search thru that PG… see how often those terms occur within those custom impostor and plugin classes. Get a “feel” for what it will take. (Yes, I realize that you are only looking for native calls and not necessarily BJS plugin/impostor support).
We need native-call examples, and it’s likely Trevor has not ever seen them either… so pressing him with capitalized “PLEASE”… likely won’t help.
I really doubt that Trevor has any more access to Ammo demos than you do. And, you might need to go to Bullet demos just to find anyone USING those parameters AT ALL. But, drop a line to the author(s) of AmmoJS… and just ask if demos with those two params being used… exist.
“PLEASE”… get some urls, show us code, and then, at minimum, hunt’n’peck Wingnut will start hacking on AmmoJS paddlewheel demo, seeing if I can get an under-the-plugin, under-the-impostor-wrapper… native-call to work.
What is taking so long? C’mon!
Possible Assistance - from pyBullet example line 9. setCollisionFilterGroupMask()
It uses a .urdf file? Universal Robotic Description Format. hmm. Program a ‘robot’… how to “apply” the collision formula(s)? hmm. Object-by-object… custom colliding-formula-values… injection? (via xml files) Nice. Build-it-yourself impostor-shape/behaviors!