version: "1.0.0" name: xb-simulator description: >- Develop and test XR Blocks apps on the desktop without a headset using the built-in simulator — a simulated user, hands, depth, and planes rendered in a normal browser, with control modes for moving the user, posing hands, or driving controllers. Use when running/iterating locally, reproducing XR interactions on desktop, posing hands for gesture work, or adding the optional 2D simulator settings UI. Covers the ?formFactor=desktop autostart, options.simulator.*, xb.SimulatorMode, the SimulatorAddons 2D UI import, and the onSimulatorStarted() hook.

xb-simulator: desktop XR simulator

The simulator runs the same app in a normal browser so you can iterate without a device. It is on by default (options.enableSimulator).

Run / autostart

npm run dev    # serves http://127.0.0.1:8080

• Click Enter Simulator on the XR button, or
• append ?formFactor=desktop to the URL to autostart the simulator, or
• set it in code:

const options = new xb.Options();
options.formFactor = 'desktop'; // autostart simulator
// or expose a button: options.xrButton.showEnterSimulatorButton = true;

Optional 2D desktop UI

Import the simulator addon to get on-screen settings/instruction panels (hand-pose picker, gamepad settings, mic button, etc.) on desktop:

import 'xrblocks/addons/simulator/SimulatorAddons.js';

Control modes

options.simulator.defaultMode = xb.SimulatorMode.POSE; // pose hands (great for gestures/hands)

SimulatorMode.POSE lets you pose virtual hands; other modes move the user or drive controllers — see `src/simulator/SimulatorOptions.ts` and src/simulator/controlModes/.

Reach limits

You can limit how far each virtual hand controller can travel from the user's shoulder origin (in meters) and restrict their movement to an angular cone (in radians) facing forward from the camera:

options.simulator.reachDistance.enabled = true;
options.simulator.reachDistance.radius = 0.75; // meters from shoulder origin
options.simulator.reachDistance.leftHandOrigin = {x: -0.2, y: -0.2, z: 0};
options.simulator.reachDistance.rightHandOrigin = {x: 0.2, y: -0.2, z: 0};
options.simulator.reachAngle.enabled = true;
options.simulator.reachAngle.angle = Math.PI; // radians (default Math.PI is a front hemisphere)

Lifecycle

onSimulatorStarted() fires when the simulator boots — a common pattern is to mirror your XR startup:

onSimulatorStarted() { this.onXRSessionStarted(); }

Notes

• The simulator provides simulated depth and planes, so `xb-depth` and

`xb-world` features work on desktop.

• demos/sim_hand_poses is a focused example of posing hands in the simulator.
• options.enableSimulator = false (or formFactor: 'xr') disables it for device-only builds.