Deprecated
This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
The leftViewMatrix
read-only property of the VRFrameData
interface returns a Float32Array
representing a 4x4 matrix that describes the view transform to be used for the left eye’s rendering.
This value may be passed directly to WebGL’s uniformMatrix4fv
function.
Important: It is highly recommended that applications use this matrix when rendering.
Syntax
var myLVM = vrFrameDataInstance.leftViewMatrix;
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 'leftViewMatrix' in that specification. |
Draft | Initial definition |
Browser compatibility
BCD tables only load in the browser
See also
- WebVR API homepage
- https://mixedreality.mozilla.org/ — demos, downloads, and other resources from the Mozilla VR team.