W3cubDocs

/DOM

VRFrameData.rightProjectionMatrix

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The rightProjectionMatrix read-only property of the VRFrameData interface returns a Float32Array representing a 4x4 matrix that describes the projection to be used for the right eye’s rendering.

This value may be passed directly to WebGL’s uniformMatrix4fv function.

Important: It is highly recommended that applications use this matrix without modification. Failure to use this projection matrix when rendering may cause the presented frame to be distorted or badly aligned, resulting in varying degrees of user discomfort.

Syntax

var myRPM = vrFrameDataInstance.rightProjectionMatrix;

Value

A Float32Array object.

Examples

var frameData = new VRFrameData();
var vrDisplay;

navigator.getVRDisplays().then(function(displays) {
  vrDisplay = displays[0];
  console.log('Display found');
  // Starting the presentation when the button is clicked: It can only be called in response to a user gesture
  btn.addEventListener('click', function() {
    vrDisplay.requestPresent([{ source: canvas }]).then(function() {        
      drawVRScene();
    });
  });
});

// WebVR: Draw the scene for the WebVR display.
function drawVRScene() {
  // WebVR: Request the next frame of the animation
  vrSceneFrame = vrDisplay.requestAnimationFrame(drawVRScene);

  // Populate frameData with the data of the next frame to display
  vrDisplay.getFrameData(frameData);

  // You can get the position, orientation, etc. of the display from the current frame's pose
  // curFramePose is a VRPose object
  var curFramePose = frameData.pose;
  var curPos = curFramePose.position;
  var curOrient = curFramePose.orientation;

  // Clear the canvas before we start drawing on it.

  gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

  // WebVR: Create the required projection and view matrix locations needed
  // for passing into the uniformMatrix4fv methods below

  var projectionMatrixLocation = gl.getUniformLocation(shaderProgram, "projMatrix");
  var viewMatrixLocation = gl.getUniformLocation(shaderProgram, "viewMatrix");

  // WebVR: Render the left eye’s view to the left half of the canvas
  gl.viewport(0, 0, canvas.width * 0.5, canvas.height);
  gl.uniformMatrix4fv(projectionMatrixLocation, false, frameData.leftProjectionMatrix);
  gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.leftViewMatrix);
  drawGeometry();

  // WebVR: Render the right eye’s view to the right half of the canvas
  gl.viewport(canvas.width * 0.5, 0, canvas.width * 0.5, canvas.height);
  gl.uniformMatrix4fv(projectionMatrixLocation, false, frameData.rightProjectionMatrix);
  gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.rightViewMatrix);
  drawGeometry();

  function drawGeometry() {
    // draw the view for each eye 
  }

    ...

  // WebVR: Indicate that we are ready to present the rendered frame to the VR display
  vrDisplay.submitFrame();
}

Note: You can see this complete code at raw-webgl-example.

Specifications

Specification Status Comment
WebVR 1.1
The definition of 'rightProjectionMatrix' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari
Basic support Yes1 2 Yes

553

584

No ? ?
Feature Android webview Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic support No Yes5 ? ? No ? ?

1. Only works on desktop in an experimental version of Chrome (other builds won't return any devices when Navigator.getVRDisplays() is invoked).

2. This feature is behind the WebVR preference. To change preferences in Chrome, visit chrome://flags.

3. Windows support was enabled in Firefox 55.

4. macOS support was enabled in Firefox 58.

5. Currently supported only by Google Daydream.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/VRFrameData/rightProjectionMatrix