Degree-of-freedom locking about mujoco HOT 4 OPEN

Yes and no.

Very generally, MuJoCo was designed to simulate medium sized scenes, so handling of large scenes can be improved in many ways, and large scenes are indeed one of our top priorities. We've already made changes and have several more coming soon that will reduce and eventually eliminate quadratic memory allocation in mjData (MuJoCo uses sparse math, but in some important places assumes for convenience that dense memory is available). This will enable the most basic of all large-scene features: fit the scene in memory 🤠

Following this, a very low hanging fruit which we intend to work on soon is MuJoCo's inefficient broadphase collision detection, which prunes far too few narrowphase calls. This leads to a large unnecessary slowdown, yet is not hard to improve.

Only after these steps are complete does it make sense to move towards the two features required for actual large scenes: dof freezing and parallel handling of contact islands (cliques of contacts and dofs). There are many decisions to make here and different possible approaches, and these will take time to figure out.

In terms of timeline, I can say that the features described in the first two paragraphs are planned for 2023. It is fair to hope that the detailed design of the dof freezing and contact islands will also happen, but it's hard to imagine the implementation being completed this year.

I hope this makes sense.

from mujoco.

It's good to hear that this is part of your plans. Looking forward to the improvements.

from mujoco.

@yuvaltassa are there any updates on this feature? If not, do you have any suggestions on the best way to go about it?

from mujoco.

+1 on this feature, it would be nice to have the option to lock and unlock joints for tuning actuators.

from mujoco.