Error creating viewer: Sim->Graphics is nullptr

[song-hl]

How can I get image obs from isaacgym in a headless device? even if when I use a HEADED device , and set headless = False, virtual_screen_capture =True, I tried following code.

import isaacgym
import isaacgymenvs
import torch

envs = isaacgymenvs.make(
    seed=0, 
    task="Ant", 
    num_envs=20, 
    sim_device="cuda:0",
    rl_device="cuda:0",
    headless=False, 
    virtual_screen_capture=True, 
)
print("Observation space is", envs.observation_space)
print("Action space is", envs.action_space)
obs = envs.reset()
img = envs.render()
for _ in range(20):
    obs, reward, done, info = envs.step(
        torch.rand((2000,)+envs.action_space.shape, device="cuda:0")
    )

GOT OUTPUT WITH ERROR:[Error] [carb.gym.plugin] Error creating viewer: Sim->Graphics is nullptr It seems that the error raised by 235 line in vec_task.py self.viewer = self.gym.create_viewer( self.sim, gymapi.CameraProperties()) I can't find a solution to it , please help me.

[song-hl]

What's more. Is there some methods I can get a images obs from the env. And is it possible for isaacgymenv to train a RL agent with a image input

[hu-hy17]

I've found the solution for your first question. graphics_device_id need to be passed to isaacgymenvs.make, otherwise it will be set to -1 by default and cause the error. I use the following code and it works well.

envs = isaacgymenvs.make(
    seed=0,
    task="Ant",
    num_envs=2000,
    sim_device="cuda:0",
    rl_device="cuda:0",
    graphics_device_id=0,
    headless=False
)

[xizaoqu]

I've found the solution for your first question. graphics_device_id need to be passed to isaacgymenvs.make, otherwise it will be set to -1 by default and cause the error. I use the following code and it works well.

envs = isaacgymenvs.make(
    seed=0,
    task="Ant",
    num_envs=2000,
    sim_device="cuda:0",
    rl_device="cuda:0",
    graphics_device_id=0,
    headless=False
)

Thank you, ashuai.

[wangjunyi9999]

I've found the solution for your first question. graphics_device_id need to be passed to isaacgymenvs.make, otherwise it will be set to -1 by default and cause the error. I use the following code and it works well.

envs = isaacgymenvs.make(
    seed=0,
    task="Ant",
    num_envs=2000,
    sim_device="cuda:0",
    rl_device="cuda:0",
    graphics_device_id=0,
    headless=False
)

Thanks, it works fine for me. Or set headless as True to close the render window, but it seems not a good idea.

[zhuoqun-chen]

I've found the solution for your first question. graphics_device_id need to be passed to isaacgymenvs.make, otherwise it will be set to -1 by default and cause the error. I use the following code and it works well.

envs = isaacgymenvs.make(
    seed=0,
    task="Ant",
    num_envs=2000,
    sim_device="cuda:0",
    rl_device="cuda:0",
    graphics_device_id=0,
    headless=False
)

Thanks, it works fine for me. Or set headless as True to close the render window, but it seems not a good idea.

Thank you! Setting either to graphics_device_id=0 or headless=True solves my problem.