Circles of low density can create a bias when bouncing about matter-js HOT 3 CLOSED

I think this is a precision issue caused by the fact that circles are not true circles in the current implementation.

Using this code I've increased the precision of the approximated circles (the final argument of Bodies.circle):

Matter.World.add(engine.world, Matter.Bodies.circle(180.5, 25.5, 51, { isStatic: false, density: 0.001, friction: 0.1, restitution: 0.8 }, 100)); 
Matter.World.add(engine.world, Matter.Bodies.circle(380.5, 25.5, 51, { isStatic: false, density: 0.1, friction: 0.1, restitution: 0.8 }, 100));   
Matter.World.add(engine.world, Matter.Bodies.rectangle(285.5, 523.5, 502, 102, { isStatic: true, density: 1.0, friction: 0.0, restitution: 1.0 }));

This seems to give the result you expected, I think?

I wouldn't advise setting such a high circle precision generally though, as it is it will be a performance hit - you may have to wait until I get around to implementing true circles.

from matter-js.

Yes, this does improve it. I had tried increasing the precision on my own circles, but not enough where I noticed the problem fixed. I also suspect my circles might be landing on a vertex slightly differently than yours as well so I will try a few things there.

from matter-js.

I think this is indeed the issue, so closing this one for now but feel free to update if you find more problems.

Hopefully by the next release I'll have true circles implemented and this won't be a problem

from matter-js.