## [V1 to v2]Friction and bounciness

Discuss any questions about BEPUphysics or problems encountered.
Darkon76
Posts: 23
Joined: Mon Mar 27, 2017 12:33 pm

### [V1 to v2]Friction and bounciness

Hello,

At bepu 1 each entity can have a friction and a bounciness, in v2 we need to calculate a physics material between two objects.

Which is the formula to have a friction and bounciness similar to bepu1? I'm interested at the extremes 0 and 1, and only one object is kinematic.

How does the inertia.InverseInertiaTensor affects those values?

Regards.

Norbo
Posts: 4910
Joined: Tue Jul 04, 2006 4:45 am

### Re: [V1 to v2]Friction and bounciness

Which is the formula to have a friction and bounciness similar to bepu1?
v1 had a callback that could be set to anything, but the default was multiplicative: https://github.com/bepu/bepuphysics1/bl ... ger.cs#L77

It's worth noting that bounciness does not exist as it did in v1: https://github.com/bepu/bepuphysics2/issues/52

It comes with some fundamental issues, so I've been waiting to see how long I can get away with not having it at all
How does the inertia.InverseInertiaTensor affects those values?
The inertia tensor affects angular motion. You can think of it as 'angular mass'. Objects with higher inertia around an axis will require larger torques to achieve the same angular acceleration around that axis. So it's not directly related to material properties, but a very low inertia (or high inverse inertia) object will be more likely to roll instead of slide, all else being equal.