Setting model state in Unity

[Balint-H]

Hello, I'm taking a look at the new Unity plug-in and I'm really excited to apply it to a ML Agents learning environment.

Between episodes I'd like to reset the model to a state determined by a Unity MonoBehaviour. I'd like to set the root position and each joints rotation, as well as linear and angular velocities. This would have to be with a "Teleporting" method if possible (to avoid spikes in velocity/momentum).

Previously I had a setup like this with Unity ArticulationBodies. What is the right way to do this with the MuJoCo API with the Unity Plug-in?

Thank you!

[erez-tom]

You can set the MuJoCo state (e.g., data->qpos for root position and joint angles, and data->qvel for respective velocities) at any stage. In order to force Unity to sync to the new state, first call mj_kinematics(model, data) (to update e.g., data->xpos according to the new qpos) and then MjScene.SyncUnityToMjState() (to update Unity transforms according to the new xpos).

You can see an example of this workflow in MjScene.RecreateScene().