[Question] why d4rl's state dims are different from gym's ?

[wydxry]

for example, bullet-hopper-medium-v0's state dim is 15，and Hopper-v4's state dim is 11, so where can i find the meaning of your data, and what difference above these? https://www.gymlibrary.dev/environments/mujoco/hopper/

[pseudo-rnd-thoughts]

Hi, the pybullet and mujoco implementations of the hooper environment are different implementations. You might need to look at the specification files for their differences

[wydxry]

So bullet and mujoco are different engine for same env, Thank you for your useful and timely answer！I will try mujoco imple...