Yuval Tassa
a264d0bc8b
https://youtu.be/GioWwB36XHI The new geom attribute adhesion (units of force, signed; pair-level override) translates the contact friction cone along its normal so that the force origin lies strictly inside it. Consequences: each contact can pull with up to the given force before breaking, and the tangential friction budget becomes mu*(f_N + adhesion) -- the Mohr-Coulomb yield condition with cohesion c = mu*adhesion -- so lightly-squeezed grasps retain a guaranteed friction floor. A translated cone factors exactly into {constant attractive force} + {original cone}, so no solver kernels change. The implementation is this factorization: a constant attraction along contact normals accumulated into the new mjData.qfrc_adhesion (summed into qfrc_passive), plus a bias of adhesive contact rows' reference acceleration (aref += R*adhesion), which makes resting penetration exactly independent of adhesion. Contacts of adhesive pairs remain active throughout the gap zone, producing rows with positive violation whose reference acceleration pulls: a tether that resists pull-off smoothly, captures objects released within the band into steady contact, and detaches at the specified force. Adhesion values of the two geoms combine by sum; explicit pairs override. mj_contactForce reports the net interface force (cone force minus the adhesive pull), whose normal component can now be negative. Negative adhesion is allowed and produces a repulsive offset (air hockey). PiperOrigin-RevId: 950858148 Change-Id: I879c08eba7ae501e5c0f8c2f807167344da4c2bc
Unity Plug-in
The MuJoCo Unity plug-in allows the Unity Editor and runtime to use the MuJoCo physics engine. Users can import MJCF files and edit the models in the Editor. The plug-in relies on Unity for most aspects -- assets, game logic, simulation time -- but uses MuJoCo to determine how objects move, giving the designer access to MuJoCo's full API. See documentation and installation instructions here.