BabylonJS/Babylon.js · error

cameraUniqueId must be a number.

Error message

cameraUniqueId must be a number.

What it means

Thrown by the 'screenshot' command when args.cameraUniqueId is provided but cannot be parsed by parseInt(…, 10). Only fully numeric strings are accepted; anything else (letters, empty string, hex notation) yields NaN and triggers this error.

Source

Thrown at packages/dev/inspector-v2/src/services/cli/screenshotCommandService.ts:53

                    name: "precision",
                    description: "Resolution multiplier (e.g. 2 for double resolution). Defaults to 1.",
                    required: false,
                },
            ],
            executeAsync: async (args) => {
                const scene = sceneContext.currentScene;
                if (!scene) {
                    throw new Error("No active scene.");
                }

                const engine = scene.getEngine();

                // Resolve camera: explicit uniqueId, or active/frame-graph camera.
                let camera;
                if (args.cameraUniqueId) {
                    const cameraId = parseInt(args.cameraUniqueId, 10);
                    if (isNaN(cameraId)) {
                        throw new Error("cameraUniqueId must be a number.");
                    }
                    camera = scene.cameras.find((c) => c.uniqueId === cameraId);
                    if (!camera) {
                        throw new Error(`No camera found with uniqueId ${cameraId}.`);
                    }
                } else {
                    camera = scene.frameGraph ? FrameGraphUtils.FindMainCamera(scene.frameGraph) : scene.activeCamera;
                }

                if (!camera) {
                    throw new Error("No camera available for screenshot.");
                }

                const precision = args.precision !== undefined ? Number(args.precision) : 1;
                if (!Number.isFinite(precision) || precision <= 0) {
                    throw new Error("precision must be a finite number greater than 0.");
                }

View on GitHub (pinned to 0592b347b8)

Solutions

1. Pass the camera's numeric uniqueId as a decimal string (find it via a scene query command).
2. Omit cameraUniqueId entirely to let the command auto-resolve the active/frame-graph camera.
3. Trim/normalize the value before passing it; leading/trailing spaces are tolerated by parseInt but other characters are not.

Example fix

// before
await execute("screenshot", { cameraUniqueId: "mainCamera" });
// after
await execute("screenshot", { cameraUniqueId: "7" });

if (args.cameraUniqueId != null && Number.isNaN(Number.parseInt(args.cameraUniqueId, 10))) throw new TypeError(`cameraUniqueId must be a decimal number, got: ${JSON.stringify(args.cameraUniqueId)}`);

function isNumericId(v: unknown): v is string { return typeof v === "string" && /^-?\d+$/.test(v.trim()); }

try {
  await screenshot({ cameraUniqueId: camId });
} catch (e) {
  if (e instanceof Error && e.message === "cameraUniqueId must be a number.") {
    return screenshot({}); // fall back to active camera
  }
  throw e;
}

When it happens

Trigger: Calling screenshot with cameraUniqueId="cam1", "", "0x10", or any non-decimal value while the argument is truthy.

Common situations: Passing a camera name instead of its uniqueId; copying an object reference or label from the scene explorer; a script interpolating an undefined variable into the string.

Related errors

• uniqueId must be a number.
• No camera found with uniqueId ${cameraId}.
• No camera available for screenshot.
• precision must be a finite number greater than 0.
• width must be a finite positive integer.

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/e52db798a5bc4282. Report an issue: GitHub.