PG: https://playground.babylonjs.com/#5W5B6W#74
Why does the rotor behave incorrectly? I think it is pushed by 2 walls, which are found in front of him and behind him. But why do they do it if the rotor does not concern them?
Yes, it looks like the rotor bounces between the 2 boxes. Once 1 of the box is pushed a little, it doesn’t bounce anymore.
But why is this happening? Now in my code the box is visually at least doesn’t contact with the rotor
f I move the box along z, there will be some gap between the box and the rotor and the balls will be able to pop out
Can I make the rotor only interact with spheres and ignore boxes?
What do you need the boxes for?
this is a lottery drum, there will be balls inside which the rotor will twist. To prevent the balls from falling out
You can try to use group/mask with ammojs.
in Use a Physics Engine - Babylon.js Documentation search for ‘group’
So you can disable collisions between the rotor and the boxes.
I read that ammo don’t provide such an opportunity
It’s possible.
https://playground.babylonjs.com/#5W5B6W#76
I just set the group and mask values to disable collisions and show you the feature. With appropriate values, you should be able to fine tweak the collisions.
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Oh, super, thanks!
I couldn’t understand why the masks and groups did not work for me on a local project. I decided that this is because of the version of Babylon that I put through npm packages. Because if you download Babylon from the site, then everything works. Don’t tell me what’s the matter?
Did you try with babylonjs nightly build?
nightly build. What is this? 
I’m building using webpack. I have analyzed and I can say with confidence that only version 4.2.0 supports masks and groups.
And one more question, tell me please. I can adjust the groups and masks so that the wall and the rotor do not collide with each other, but at the same time so that they both collide with the balls
for example, set the mask to rotor, box, ball to 1, 2,4 mask to 4, 4, 7 respectively
so, rotor collides with ball only
box with balls only
ball with rotor, box and balls