vtk.js

VR

Live example

## Viewing Scenes with WebXR

vtk.js supports virtual reality rendering via the WebXR device API for most standalone and PC headsets.

Developers seeking to develop VR experiences without hardware may make use of the Mozilla WebXR emulator extension at https://github.com/MozillaReality/WebXR-emulator-extension with these installation steps:

• Install the WebXR extension on either Chrome or Firefox.
• Close and reopen the browser.
• Press F12 to access the browser console.
• Select the “WebXR” tab to selected XR emulated hardware and view controls.

Source

// For streamlined VR development install the WebXR emulator extension
// https://github.com/MozillaReality/WebXR-emulator-extension

import '@kitware/vtk.js/favicon';

// Load the rendering pieces we want to use (for both WebGL and WebGPU)
import '@kitware/vtk.js/Rendering/Profiles/Geometry';

import vtkActor from '@kitware/vtk.js/Rendering/Core/Actor';
import vtkCalculator from '@kitware/vtk.js/Filters/General/Calculator';
import vtkConeSource from '@kitware/vtk.js/Filters/Sources/ConeSource';
import vtkFullScreenRenderWindow from '@kitware/vtk.js/Rendering/Misc/FullScreenRenderWindow';
import vtkWebXRRenderWindowHelper from '@kitware/vtk.js/Rendering/WebXR/RenderWindowHelper';
import vtkMapper from '@kitware/vtk.js/Rendering/Core/Mapper';
import { AttributeTypes } from '@kitware/vtk.js/Common/DataModel/DataSetAttributes/Constants';
import { FieldDataTypes } from '@kitware/vtk.js/Common/DataModel/DataSet/Constants';
import { XrSessionTypes } from '@kitware/vtk.js/Rendering/WebXR/RenderWindowHelper/Constants';

// Force DataAccessHelper to have access to various data source
import '@kitware/vtk.js/IO/Core/DataAccessHelper/HtmlDataAccessHelper';
import '@kitware/vtk.js/IO/Core/DataAccessHelper/HttpDataAccessHelper';
import '@kitware/vtk.js/IO/Core/DataAccessHelper/JSZipDataAccessHelper';

import vtkResourceLoader from '@kitware/vtk.js/IO/Core/ResourceLoader';

// Custom UI controls, including button to start XR session
import controlPanel from './controller.html';

// Dynamically load WebXR polyfill from CDN for WebVR and Cardboard API backwards compatibility
if (navigator.xr === undefined) {
  vtkResourceLoader
    .loadScript(
      'https://cdn.jsdelivr.net/npm/webxr-polyfill@latest/build/webxr-polyfill.js'
    )
    .then(() => {
      // eslint-disable-next-line no-new, no-undef
      new WebXRPolyfill();
    });
}

// ----------------------------------------------------------------------------
// Standard rendering code setup
// ----------------------------------------------------------------------------

const fullScreenRenderer = vtkFullScreenRenderWindow.newInstance({
  background: [0, 0, 0],
});
const renderer = fullScreenRenderer.getRenderer();
const renderWindow = fullScreenRenderer.getRenderWindow();
const XRHelper = vtkWebXRRenderWindowHelper.newInstance({
  renderWindow: fullScreenRenderer.getApiSpecificRenderWindow(),
});

// ----------------------------------------------------------------------------
// Example code
// ----------------------------------------------------------------------------
// create a filter on the fly, sort of cool, this is a random scalars
// filter we create inline, for a simple cone you would not need
// this
// ----------------------------------------------------------------------------

const coneSource = vtkConeSource.newInstance({ height: 100.0, radius: 50 });
const filter = vtkCalculator.newInstance();

filter.setInputConnection(coneSource.getOutputPort());
// filter.setFormulaSimple(FieldDataTypes.CELL, [], 'random', () => Math.random());
filter.setFormula({
  getArrays: (inputDataSets) => ({
    input: [],
    output: [
      {
        location: FieldDataTypes.CELL,
        name: 'Random',
        dataType: 'Float32Array',
        attribute: AttributeTypes.SCALARS,
      },
    ],
  }),
  evaluate: (arraysIn, arraysOut) => {
    const [scalars] = arraysOut.map((d) => d.getData());
    for (let i = 0; i < scalars.length; i++) {
      scalars[i] = Math.random();
    }
  },
});

const mapper = vtkMapper.newInstance();
mapper.setInputConnection(filter.getOutputPort());

const actor = vtkActor.newInstance();
actor.setMapper(mapper);
actor.setPosition(0.0, 0.0, -20.0);

renderer.addActor(actor);
renderer.resetCamera();
renderWindow.render();

// -----------------------------------------------------------
// UI control handling
// -----------------------------------------------------------

fullScreenRenderer.addController(controlPanel);
const representationSelector = document.querySelector('.representations');
const resolutionChange = document.querySelector('.resolution');
const vrbutton = document.querySelector('.vrbutton');

representationSelector.addEventListener('change', (e) => {
  const newRepValue = Number(e.target.value);
  actor.getProperty().setRepresentation(newRepValue);
  renderWindow.render();
});

resolutionChange.addEventListener('input', (e) => {
  const resolution = Number(e.target.value);
  coneSource.setResolution(resolution);
  renderWindow.render();
});

vrbutton.addEventListener('click', (e) => {
  if (vrbutton.textContent === 'Send To VR') {
    XRHelper.startXR(XrSessionTypes.HmdVR);
    vrbutton.textContent = 'Return From VR';
  } else {
    XRHelper.stopXR();
    vrbutton.textContent = 'Send To VR';
  }
});

// -----------------------------------------------------------
// Make some variables global so that you can inspect and
// modify objects in your browser's developer console:
// -----------------------------------------------------------

global.source = coneSource;
global.mapper = mapper;
global.actor = actor;
global.renderer = renderer;
global.renderWindow = renderWindow;