{"record":{"id":"c8b286b7fb251b38","repo":"BabylonJS/Babylon.js","slug":"cannot-create-the-xr-graphics-binding-before-the-x","errorCode":null,"errorMessage":"Cannot create the XR graphics binding before the XR session is initialized.","messagePattern":"Cannot create the XR graphics binding before the XR session is initialized\\.","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/dev/core/src/XR/webXRSessionManager.ts","lineNumber":310,"sourceCode":"        const pose = this.currentFrame.getViewerPose(this.referenceSpace);\r\n        if (!pose || viewIndex >= pose.views.length) {\r\n            throw new RangeError(`XR view ${viewIndex} is not available in the current viewer pose.`);\r\n        }\r\n        return pose.views[viewIndex];\r\n    }\r\n\r\n    /**\r\n     * Obtains the XR graphics binding for the current session, creating it lazily.\r\n     * This is the API-agnostic seam used by WebGL and WebGPU XR features to share a binding.\r\n     * @returns the XR graphics binding for the current session\r\n     * @internal\r\n     */\r\n    public _getGraphicsBinding(): WebXRGraphicsBinding {\r\n        if (!this._engine) {\r\n            throw new Error(\"Cannot create the XR graphics binding: the engine has been disposed.\");\r\n        }\r\n        if (!this.session) {\r\n            throw new Error(\"Cannot create the XR graphics binding before the XR session is initialized.\");\r\n        }\r\n        if (!this._graphicsBinding) {\r\n            this._graphicsBinding = this._engine.isWebGPU\r\n                ? WebXRWebGPUGraphicsBinding.CreateFromEngine(this.session, this._engine)\r\n                : WebXRWebGLGraphicsBinding.CreateFromEngine(this.session, this._engine);\r\n        }\r\n        return this._graphicsBinding;\r\n    }\r\n\r\n    /**\r\n     * Creates a WebXRRenderTarget object for the XR session\r\n     * @param options optional options to provide when creating a new render target\r\n     * @returns a WebXR render target to which the session can render\r\n     */\r\n    public getWebXRRenderTarget(options?: WebXRManagedOutputCanvasOptions): WebXRRenderTarget {\r\n        const engine = this.scene.getEngine();\r\n        if (this._xrNavigator.xr.native) {\r\n            return new NativeXRRenderTarget(this);\r","sourceCodeStart":292,"sourceCodeEnd":328,"githubUrl":"https://github.com/BabylonJS/Babylon.js/blob/0592b347b8a4ee0236089ea86a749cacfdb266d8/packages/dev/core/src/XR/webXRSessionManager.ts#L292-L328","documentation":"The XR graphics binding must be created with a live XRSession (WebGL/WebGPU binding constructors take the session). _getGraphicsBinding throws if this.session is null, i.e. the manager has no initialized session yet — the binding cannot exist before a session does.","triggerScenarios":"Calling _getGraphicsBinding() (or a layer/feature that requests it) after creating the WebXRSessionManager but before initializeAsync/setSession established a session; using a manager whose session ended and was cleared; attempting to register a WebXR layer manually without starting a session first.","commonSituations":"Instantiating WebXRLayerRenderTargetTextureProvider or custom composition layers at setup time instead of after session start; a feature's attach() running before the session promise resolved; reusing a session manager object after session end for a new attempt.","solutions":["Start the session first (await xr.initializeAsync(); await xr.setSessionAsync(...) or Helper.createDefaultSessionAsync) before any code that touches graphics bindings.","Check `xr.sessionManager.session != null` before creating layers/features that need the binding.","Initialize features after the session is ready — use onXRSessionInit / session observables rather than constructor-time setup.","Create a fresh session manager per session instead of reusing one whose session ended."],"exampleFix":"// before\nconst xr = new WebXRSessionManager(scene);\nconst provider = new WebXRWebGLRenderTargetTextureProvider(engine, xr.sessionManager); // no session yet\n// after\nconst xr = new WebXRSessionManager(scene);\nawait xr.setSessionAsync(await navigator.xr.requestSession('immersive-vr'));\nconst provider = new WebXRWebGLRenderTargetTextureProvider(engine, xr.sessionManager);","handlingStrategy":"validation","validationCode":"if (!xr.session) {\n  throw new Error('XR session must be started before creating graphics bindings');\n}\nconst binding = xr._getGraphicsBinding();","typeGuard":"function sessionActive(xr: WebXRSessionManager): xr is WebXRSessionManager & { session: XRSession } {\n  return xr.session != null;\n}","tryCatchPattern":"try {\n  const binding = xr._getGraphicsBinding();\n} catch (e) {\n  if (e instanceof Error && e.message.includes('before the XR session')) {\n    console.warn('Graphics binding requested before session start — deferring');\n    return null;\n  }\n  throw e;\n}","preventionTips":["Await initializeAsync + setSessionAsync before any layer/feature setup","Check sessionManager.session before building composition layers","Initialize WebXR features from session-start observables, not constructors","Create a new manager per session; do not reuse managers whose session ended"],"tags":["webxr","session-lifecycle","initialization-order"],"backgroundTag":"xr-session-not-initialized","analyzedSha":"0592b347b8a4ee0236089ea86a749cacfdb266d8","analyzedAt":"2026-08-30T15:11:20.442Z","schemaVersion":2},"datasetVersion":"2026-08-30T18:17:15.746Z"}