BabylonJS/Babylon.js · error

DumpData: No WebGL context available. Cannot dump data.

Error message

DumpData: No WebGL context available. Cannot dump data.

What it means

DumpTools' pure (DOM-independent) dump path lazily imports ThinEngine to get a GPU context for encoding dump data. If ThinEngine.IsSupported is false — no usable WebGL — there is no way to encode the dump, so the library throws this explicit error instead of failing later with an opaque context error.

Source

Thrown at packages/dev/core/src/Misc/dumpTools.pure.ts:39

        renderer: EffectRenderer;
        wrapper: EffectWrapper;
    };
};

let ResourcesPromise: Promise<DumpResources> | null = null;

async function _CreateDumpResourcesAsync(): Promise<DumpResources> {
    // Create a compatible canvas. Prefer an HTMLCanvasElement if possible to avoid alpha issues with OffscreenCanvas + WebGL in many browsers.
    const canvas = (EngineStore.LastCreatedEngine?.createCanvas(100, 100) ?? new OffscreenCanvas(100, 100)) as HTMLCanvasElement | OffscreenCanvas; // will be resized later
    if (canvas instanceof OffscreenCanvas) {
        Logger.Warn("DumpData: OffscreenCanvas will be used for dumping data. This may result in lossy alpha values.");
    }

    // If WebGL via ThinEngine is not available, we cannot encode the data.
    // If https://github.com/whatwg/html/issues/10142 is resolved, we can migrate to just BitmapRenderer and avoid an engine dependency altogether.
    const { ThinEngine: thinEngineClass } = await import("../Engines/thinEngine.pure");
    if (!thinEngineClass.IsSupported) {
        throw new Error("DumpData: No WebGL context available. Cannot dump data.");
    }

    const options = {
        preserveDrawingBuffer: true,
        depth: false,
        stencil: false,
        alpha: true,
        premultipliedAlpha: false,
        antialias: false,
        failIfMajorPerformanceCaveat: false,
    };
    const engine = new thinEngineClass(canvas, false, options);

    // remove this engine from the list of instances to avoid using it for other purposes
    EngineStore.Instances.pop();
    // However, make sure to dispose it when no other engines are left
    EngineStore.OnEnginesDisposedObservable.add((e) => {
        // guaranteed to run when no other instances are left

View on GitHub (pinned to 0592b347b8)

Solutions

1. Run in an environment with WebGL available, or enable SwiftShader/llvmpipe software GL in headless CI (e.g. --use-gl=swiftshader in Chromium)
2. Check ThinEngine.IsSupported (or create an engine and check engine.isSupported) before attempting a dump and surface a friendly message instead
3. Use a non-WebGL dump path if available (e.g. plain canvas 2D rendering of the data) instead of the GPU-encoded dump tools
4. If WebGL worked before, investigate context loss / driver blocklist (chrome://gpu) and request a new context

Example fix

// before
await DumpDataAsync(texture, dumpOptions);
// after
if (!ThinEngine.IsSupported) {
  console.warn('WebGL unavailable; skipping dump');
} else {
  await DumpDataAsync(texture, dumpOptions);
}

const { ThinEngine } = await import('../Engines/thinEngine.pure');
if (!ThinEngine.IsSupported) {
  throw new Error('WebGL is not available in this environment; dump tools cannot run');
}

function webglAvailable(): boolean {
  try {
    const c = document.createElement('canvas');
    return !!(c.getContext('webgl2') || c.getContext('webgl'));
  } catch {
    return false;
  }
}

try {
  await DumpDataAsync(target, options);
} catch (e) {
  if (e instanceof Error && e.message.includes('No WebGL context available')) {
    console.warn('Skipping dump: WebGL not supported in this environment');
  } else {
    throw e;
  }
}

When it happens

Trigger: Calling dump-data APIs (e.g. DumpData/DumpDataAsync via _CreateDumpResourcesAsync) in an environment without WebGL support — headless Node, workers with no canvas/GL, browsers with WebGL disabled, or after a context-loss.

Common situations: Running screenshot/dump tests in CI (headless, no GPU or no swiftshader); WebGL blocked by browser flags or driver blocklists; using the pure dump tools outside a browser page that provides a WebGL context.

Related errors

• WebGL not supported
• Atmosphere is not supported on WebGL ${engine.version}.
• Instanced arrays are required for MSDF text rendering.
• Unable to create multi sampled framebuffer
• Invalid Space Warp framebuffer

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/c215f74090685fab. Report an issue: GitHub.