Implementation:Google deepmind Dm control Render Backend Selection

Metadata	Value
Implementation	Render Backend Selection
Domain	Reinforcement_Learning, Physics_Simulation, Computer_Graphics
Source	dm_control
Workflow	Control_Suite_RL_Training
Last Updated	2026-02-15 00:00 GMT

Overview

Concrete tool for selecting and instantiating the OpenGL rendering context used by MuJoCo inside dm_control, supporting GLFW, EGL, and OSMesa backends.

Description

The dm_control._render package initialises a module-level Renderer callable and a BACKEND string at import time. If the MUJOCO_GL environment variable is set, the module attempts to import the corresponding backend and raises a RuntimeError if the value is unrecognised or the import fails. If MUJOCO_GL is not set, the module tries GLFW, EGL, and OSMesa in that order, selecting the first that imports successfully. If no backend can be imported, Renderer is set to a stub that raises RuntimeError on invocation.

The module also exposes USING_GPU, a boolean that is True when the active backend is either GLFW or EGL.

Usage

Use this implementation when:

You need to configure rendering before loading a Control Suite environment that produces pixel observations.
You want to verify which rendering backend is active in a running process.
You need to force a specific backend for reproducibility or hardware compatibility.

Code Reference

Attribute	Detail
Source Location	`dm_control/_render/__init__.py:L1-109`
Module-level Variables	`BACKEND` (str or None), `Renderer` (callable), `USING_GPU` (bool)
Import	`from dm_control._render import BACKEND, Renderer, USING_GPU`

The MUJOCO_GL environment variable accepts the following values:

Backend	Accepted Values	Context Type
GLFW	`glfw`, `on`, `enable`, `enabled`, `true`, `1`, `""`	`GLFWContext`
EGL	`egl`	`EGLContext`
OSMesa	`osmesa`	`OSMesaContext`
Disabled	`off`, `disable`, `disabled`, `false`, `0`	Raises `RuntimeError` on use

I/O Contract

Inputs

Name	Type	Description
`MUJOCO_GL` (env var)	str	Optional. One of the accepted backend values listed above. Controls which OpenGL backend is loaded.

Outputs

Name	Type	Description
`BACKEND`	str or None	Canonical name of the active backend (`"glfw"`, `"egl"`, `"osmesa"`), or `None` if no backend could be imported.
`Renderer`	callable	A context-manager class (e.g. `GLFWContext`, `EGLContext`, `OSMesaContext`) that can be called with `(max_width, max_height)` to create an OpenGL context.
`USING_GPU`	bool	`True` if `BACKEND` is `"glfw"` or `"egl"`.

Usage Examples

Force EGL for headless GPU rendering:

export MUJOCO_GL=egl
python train.py

Force OSMesa for CPU-only rendering:

export MUJOCO_GL=osmesa
python train.py

Query the active backend in Python:

from dm_control._render import BACKEND, USING_GPU

print(f"Active rendering backend: {BACKEND}")
print(f"GPU rendering available: {USING_GPU}")

Disable rendering entirely (useful when only collecting state observations):

export MUJOCO_GL=off
python train_state_only.py

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Principle

Implementation

Heuristic

Environment