OVR_multiview2 extension
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
The OVR_multiview2 extension is part of the WebGL API and adds support for rendering into multiple views simultaneously. This especially useful for virtual reality (VR) and WebXR.
For more information, see also:
- Multiview on WebXR
- Multiview in babylon.js
- Optimizing Virtual Reality: Understanding Multiview
- Multiview WebGL Rendering for Meta Quest
WebGL extensions are available using the WebGLRenderingContext.getExtension() method. For more information, see also Using Extensions in the WebGL tutorial.
Note: Support depends on the system's graphics driver (Windows+ANGLE and Android are supported; Windows+GL, Mac, Linux are not supported).
This extension is only available to WebGL 2 contexts as it needs GLSL 3.00 and texture arrays.
Currently, there is no way to use multiview to render to a multisampled backbuffer, so you should create contexts with antialias: false. However, the Oculus browser (6+) also supports multisampling using the OCULUS_multiview extension. See also this WebGL issue.
Constants
This extension exposes 4 constants that can be used in getParameter() or getFramebufferAttachmentParameter().
FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR-
Number of views of the framebuffer object attachment.
FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR-
Base view index of the framebuffer object attachment.
MAX_VIEWS_OVR-
The maximum number of views. Most VR headsets have two views, but there are prototypes of headset with ultra-wide FOV using 4 views which is currently the maximum number of views supported by multiview.
FRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_OVR-
If baseViewIndex is not the same for all framebuffer attachment points where the value of
FRAMEBUFFER_ATTACHMENT_OBJECT_TYPEis notNONE, the framebuffer is considered incomplete. CallingcheckFramebufferStatusfor a framebuffer in this state returnsFRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_OVR.
Instance methods
framebufferTextureMultiviewOVR()-
Simultaneously renders to multiple elements of a 2D texture array.
Examples
This example is taken from the specification.
const gl = document
.createElement("canvas")
.getContext("webgl2", { antialias: false });
const ext = gl.getExtension("OVR_multiview2");
const fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);
const colorTex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D_ARRAY, colorTex);
gl.texStorage3D(gl.TEXTURE_2D_ARRAY, 1, gl.RGBA8, 512, 512, 2);
ext.framebufferTextureMultiviewOVR(
gl.DRAW_FRAMEBUFFER,
gl.COLOR_ATTACHMENT0,
colorTex,
0,
0,
2,
);
const depthStencilTex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D_ARRAY, depthStencilTex);
gl.texStorage3D(gl.TEXTURE_2D_ARRAY, 1, gl.DEPTH32F_STENCIL8, 512, 512, 2);
ext.framebufferTextureMultiviewOVR(
gl.DRAW_FRAMEBUFFER,
gl.DEPTH_STENCIL_ATTACHMENT,
depthStencilTex,
0,
0,
2,
);
gl.drawElements(/* … */); // draw will be broadcasted to the layers of colorTex and depthStencilTex.
Shader code
#version 300 es
#extension GL_OVR_multiview2 : require
precision mediump float;
layout (num_views = 2) in;
in vec4 inPos;
uniform mat4 u_viewMatrices[2];
void main() {
gl_Position = u_viewMatrices[gl_ViewID_OVR] * inPos;
}
Also, see this three.js demo for a live multiview example.
Specifications
| Specification |
|---|
| WebGL OVR_multiview2 Extension Specification |
Browser compatibility
| desktop | mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
OVR_multiview2
|
|
|
|
|
|
|
|
|
|
|
|
|
framebufferTextureMultiviewOVR
|
|
|
|
|
|
|
|
|
|
|
|
|
Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- Partial support
- Partial support
- No support
- No support