Does anyone have more information about the new friction options in PhysicsManager?
- PatchFrictionType
- OneDirectionalFrictionType
- TwoDirectionalFrictionType
Most of the things in Unity’s Physics are 1:1 mappings where possible, so you can just use Physx docs for most things.
Thanks!
Friction types in practice:
- Patch: inexpensive but unrealistic. Friction force proportional to the number of contacts. Physics materials tuned mostly via trial & error until getting a good result in each specific project. This is the model used in Unity 5, 2017, 2018.1 and 2018.2. It’s also the default model in 2018.3+.
- Two Directional:
realistic, coulomb friction. Friction behaves closely to the real world. Coefficient of friction in physic materials are precise in up to two decimals. Actual, documented coefficients of friction may be used. - EDIT:* Info updated, see next post.
I’ve found the one-directional model to be quite inconsistent, providing uncertain results such as spurious rotations in a cube sliding down a plane. I wouldn’t recommend using it.
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As this thread still appears in searches, I’m updating it with the most recent information.
THIS is the ONLY settings combo that provides physically realistic collisions and frictions in Unity 2021+:
Patch Friction Type + Improved Patch Friction.
Friction worked realistically up to Unity 4. From Unity 5 to Unity 2020 it was essentially trial & error. Not even Two Directional friction worked realistically (not sure on how I had tested it before). These settings in Unity 2021+ finally bring back physically realistic friction that works close to reality. These should be the default settings in new projects.