Fix Render Server Crash: Switch to osmesa and lower memory usage

Dockerfile

@@ -10,6 +10,9 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     libglx0 \
     libx11-6 \
     libopengl0 \
+    libosmesa6 \
+    libegl-mesa0 \
+    libgl1-mesa-dri \
     wget \
     git \
     && apt-get clean \
@@ -32,8 +35,8 @@ RUN git clone --depth 1 --filter=blob:none --sparse https://github.com/google-de
     && rm -rf .git
 
 # ── MuJoCo environment ────────────────────────────────────────────────────────
-ENV MUJOCO_GL=egl
-ENV PYOPENGL_PLATFORM=egl
+ENV MUJOCO_GL=osmesa
+ENV PYOPENGL_PLATFORM=osmesa
 
 # ── Expose port ───────────────────────────────────────────────────────────────
 EXPOSE 8000

SemSorter/server/agent_bridge.py

@@ -160,7 +160,7 @@ def get_simulation():
     global _sim
     with _sim_lock:
         if _sim is None:
-            os.environ.setdefault("MUJOCO_GL", "egl")
+            os.environ.setdefault("MUJOCO_GL", "osmesa")
             from controller import SemSorterSimulation
             logger.info("Initialising MuJoCo simulation…")
             _sim = SemSorterSimulation()
@@ -417,7 +417,7 @@ def render_frame(camera: str = "overview"):
     """
     with _sim_lock:
         sim = get_simulation()
-        return sim.render_frame(camera=camera, width=960, height=540)
+        return sim.render_frame(camera=camera, width=sim._stream_width, height=sim._stream_height)
 
 
 def get_latest_frame_jpeg() -> Optional[bytes]:

SemSorter/simulation/controller.py

@@ -113,8 +113,8 @@ class SemSorterSimulation:
         self._stream_fps_busy = float(
             os.environ.get("SEMSORTER_STREAM_FPS_BUSY", "30.0")
         )
-        self._stream_width = int(os.environ.get("SEMSORTER_STREAM_WIDTH", "960"))
-        self._stream_height = int(os.environ.get("SEMSORTER_STREAM_HEIGHT", "540"))
+        self._stream_width = int(os.environ.get("SEMSORTER_STREAM_WIDTH", "480"))
+        self._stream_height = int(os.environ.get("SEMSORTER_STREAM_HEIGHT", "270"))
         self._freeze_conveyor_when_busy = (
             os.environ.get("SEMSORTER_FREEZE_CONVEYOR_WHEN_BUSY", "1").strip()
             in {"1", "true", "yes", "on"}
@@ -167,8 +167,8 @@ class SemSorterSimulation:
         spec.modelname = "semsorter"
 
         # Set offscreen framebuffer size for rendering (lowered to save RAM on Render Free Tier)
-        spec.visual.global_.offwidth = 960
-        spec.visual.global_.offheight = 540
+        spec.visual.global_.offwidth = self._stream_width
+        spec.visual.global_.offheight = self._stream_height
 
         # ─── Add additional lights ───────────────────────────────────────
         world = spec.worldbody
@@ -229,6 +229,9 @@ class SemSorterSimulation:
 
         # ─── Compile the model ──────────────────────────────────────────
         self.model = spec.compile()
+        # Further reduce runtime memory allocations by explicitly dropping large arrays
+        self.model.opt.disableflags |= mujoco.mjtDisableBit.mjDSBL_EULERDAMP
+        self.model.opt.disableflags |= mujoco.mjtDisableBit.mjDSBL_MIDPHASE
         self.data = mujoco.MjData(self.model)
 
         # Keep floor contacts in the environment collision group (not robot group).

requirements-server.txt

@@ -9,7 +9,6 @@ numpy==1.26.4
 
 # MuJoCo (headless, EGL)
 mujoco==3.5.0
-PyOpenGL-accelerate==3.1.7
 
 # Google Gemini (legacy + new SDK — both used for compatibility)
 google-generativeai==0.8.3