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PKU-EPIC / DexGraspNet

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WRJTx, WRJTy, WRJTz, WRJRx, WRJRy, WRJRz are for which link and which coordinate system #5

Closed oxidationreduction closed 1 year ago

oxidationreduction commented 1 year ago

Hi.

I am trying to visualize the result of your outstanding model to a simulator (Sapien), which needs to load the object and the hand to a new virtual environment. I am wondering the following 6 parameters WRJTx, WRJTy, WRJTz, WRJRx, WRJRy, WRJRz are for which link and coordinate system. I thought they were of the palm_link's pose recorded in the global coordinate system but when I applied the params to the hand, the visualization result was strange.

Could you tell me those 6 params are recorded in which coordinate system, and whether they are params for the palm_link? Thank you.

I am using Allegro Hand and the object names core-jar-e93934fc1da4635d5aa09a1176194412. I transferred WRJRx, WRJRy, WRJRz to quaternion using transforms3d.euler.euler2quat(qpos['WRJRx'], qpos['WRJRy'], qpos['WRJRz'], 'sxyz').

mzhmxzh commented 1 year ago

These parameters describe the base_link's pose in the object's coordinate system. If the object is at the origin of the world coordinate system, then it should also describe the base_link's pose in the world coordinate system. The rotation is recorded in Euler angles (sxyz format). So I think your understanding is correct. I cannot guess why SAPIEN does not visualize the data correctly, but you can try this script to visualize it in Plotly.

oxidationreduction commented 1 year ago

Thank you. There is a virtual link called world in the hand's URDF and base_link is not aligned with it. I made base_link place at the world's origin and everything works smoothly both in SAPIEN and Plotly now.