Update sim/base_sim.py

sim/base_sim.py

@@ -70,10 +70,10 @@ class DefaultEnv:
         # Initialize scene (defined in subclasses)
         self.init_scene()
 
-        # Setup offscreen rendering if needed
+        # Setup offscreen rendering if needed (lazy init - renderers created on first use)
         self.offscreen = offscreen
-        if self.offscreen:
-            self.init_renderers()
+        self.renderers = {}  # Will be lazily initialized
+        self._renderers_initialized = False
         self.image_dt = self.config.get("IMAGE_DT", 0.033333)
         
         # Image publishing subprocess (initialized separately)
@@ -446,9 +446,17 @@ class DefaultEnv:
 
     def update_render_caches(self):
         """Update render cache and shared memory for subprocess."""
+        # Lazy init renderers on first call (creates OpenGL context in calling thread)
+        if not self._renderers_initialized and self.offscreen:
+            self.init_renderers()
+            self._renderers_initialized = True
+            print(f"✓ Renderers initialized lazily in thread {__import__('threading').current_thread().name}")
+        
         render_caches = {}
         for camera_name, camera_config in self.camera_configs.items():
-            renderer = self.renderers[camera_name]
+            renderer = self.renderers.get(camera_name)
+            if renderer is None:
+                continue
             if "params" in camera_config:
                 renderer.update_scene(self.mj_data, camera=camera_config["params"])
             else: