xb-simulator
Testing & QualityDevelop 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.
How to use this skill
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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=desktopto 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(); }