Fix eval for other envs

lerobot/scripts/eval.py

@@ -49,6 +49,7 @@ from torchrl.envs.batched_envs import BatchedEnvBase
 
 from lerobot.common.datasets.factory import make_offline_buffer
 from lerobot.common.envs.factory import make_env
+from lerobot.common.envs.simxarm.env import SimxarmEnv
 from lerobot.common.logger import log_output_dir
 from lerobot.common.policies.abstract import AbstractPolicy
 from lerobot.common.policies.factory import make_policy
@@ -86,7 +87,10 @@ def eval_policy(
 
         def maybe_render_frame(env: EnvBase, _):
             if save_video or (return_first_video and i == 0):  # noqa: B023
-                ep_frames.append(env.render(mode="visualization"))  # noqa: B023
+                # HACK
+                # TODO(aliberts): set render_mode for all envs
+                render_mode = "visualization" if isinstance(env, SimxarmEnv) else "rgb_array"
+                ep_frames.append(env.render(mode=render_mode))  # noqa: B023
 
         # Clear the policy's action queue before the start of a new rollout.
         if policy is not None: