在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

leftProjectionMatrix 只读特性在 VRFrameData interface returns a Float32Array representing a 4x4 matrix that describes the projection to be used for the left eye’s rendering.

This value may be passed directly to WebGL’s uniformMatrix4fv 函数。

重要 : 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.

句法

var myLPM = vrFrameDataInstance.leftProjectionMatrix;
					

值

A Float32Array 对象。

范例

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();
}
					

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

规范

规范	状态	注释
WebVR 1.1 The definition of 'leftProjectionMatrix' in that specification.	草案	初始定义

浏览器兼容性

更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
leftProjectionMatrix 弃用	Chrome No	Edge 15 — 79	Firefox 55 55 Windows support was enabled in Firefox 55. 64 macOS support was enabled in Firefox 64.	IE No	Opera ?	Safari No	WebView Android No	Chrome Android 56 — 80 Disabled 不支持 56 — 80 Disabled Only works in an experimental version of Chrome . (Other builds won't return any devices when Navigator.getVRDisplays() is invoked.) Daydream View supported in Chrome 56. Google Cardboard supported in Chrome 57. Disabled From version 56 until version 80 (exclusive): this feature is behind the WebVR preference. To change preferences in Chrome, visit chrome://flags.	Firefox Android 55	Opera Android ?	Safari iOS ?	Samsung Internet Android 6.0 6.0 Google Cardboard supported in Samsung Internet 7.0.

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

弃用。不要用于新网站。

弃用。不要用于新网站。

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

另请参阅

• WebVR API homepage
• MozVr.com — demos, downloads, and other resources from the Mozilla VR team.

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. WebVR API
2. VRFrameData
3. 构造函数

   1. VRFrameData()
4. 特性

   1. leftProjectionMatrix
   2. leftViewMatrix
   3. pose
   4. rightProjectionMatrix
   5. rightViewMatrix
   6. timestamp
5. Related pages for WebVR API

   1. Gamepad.displayId
   2. Navigator.activeVRDisplays
   3. Navigator.getVRDisplays()
   4. VRDisplay
   5. VRDisplayCapabilities
   6. VRDisplayEvent
   7. VREyeParameters
   8. VRFieldOfView
   9. VRLayerInit
   10. VRPose
   11. VRStageParameters