Updated run_tray_simulation() (safe for HuggingFace Spaces)

- Renderer(model, width, height) initializes a headless framebuffer — safe for use in headless environments like HuggingFace Spaces.
- renderer.update_scene(data) prepares the rendering scene.
- renderer.render() returns a NumPy array image (H x W x 3).
- Make sure to renderer.close() when done to release GPU/GL resources.

tray_sim.py

@@ -3,7 +3,6 @@ import numpy as np
 import imageio
 import os
 import tempfile
-from mujoco import viewer
 
 MODEL_PATH = "assets/tray.xml"
 
@@ -16,13 +15,18 @@ def run_tray_simulation(seed=0):
     data.qpos[:3] = [0.0, 0.0, 0.3 + 0.2 * np.random.rand()]  # x, y, z
     data.qvel[:] = 0
 
-    # Simulate
+    # Use mujoco.Renderer for offscreen rendering
+    renderer = mujoco.Renderer(model, width=480, height=480)
+
     frames = []
     for _ in range(200):
         mujoco.mj_step(model, data)
-        img = mujoco.mjr_render(model, data, width=480, height=480, camera=None)
+        renderer.update_scene(data)
+        img = renderer.render()
         frames.append(img)
 
+    renderer.close()
+
     # Save as GIF to temp file
     gif_path = os.path.join(tempfile.gettempdir(), f"tray_sim_{seed}.gif")
     imageio.mimsave(gif_path, frames, fps=20)