Friction does not work on heightmaps and mesh terrain [Harmonic]

[david-dorf]

When using any model on a static heightmap, objects slide without friction regardless of surface tags. Tested on Harmonic with the Moon DEM, Portuguese Ledge, and a custom mesh .dae of a Martian terrain. Robots had proper friction only on primitive geometry (box, cylinder, plane), and sometimes worked on very flat meshes.

[stevedanomodolor]

I also noticed this problem too.

[azeey]

Is this true with the Bullet physics engine as well?