Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The read-only XRWebGLLayer property framebuffer is an opaque WebGLFramebuffer which is used to buffer the rendered image if the XR compositor is being used. Otherwise, this property's value is null. The opaque framebuffer is functionally nearly the same as a standard WebGL framebuffer, except for the differences covered in the section How opaque framebuffers are special below.
A WebGLFramebuffer object representing the framebuffer into which the 3D scene is being rendered, or null if the XR compositor is disabled for the session.
The framebuffer represented by the framebuffer property is opaque. As such, its behavior is different in several ways from a standard WebGL context. These differences cause the opaque framebuffer to behave more like the default WebGL framebuffer:
framebufferTexture2D(), framebufferRenderbuffer(), deleteFramebuffer(), or getFramebufferAttachmentParameter() on an opaque framebuffer results in the WebGL error INVALID_OPERATION (0x0502).requestAnimationFrame() callback. Attempting to clear, draw to, or read from the framebuffer results in a WebGL INVALID_FRAMEBUFFER_OPERATION error (0x0506). Calling checkFramebufferStatus() on the WebGL context from outside the animation frame callback causes the WebGL FRAMEBUFFER_UNSUPPORTED error (0x8CDD) to be reported.depth property set to false will not have a depth buffer and will rely on the coordinates alone to determine distance.stencil property will not have a stencil buffer.alpha property is true when creating the layer.premultipliedAlpha context attribute is set.Note: The depth and stencil properties are not required to be supported in order for a browser to be construed as having full WebGL support.
Upon creating a new XRWebGLLayer, its new framebuffer is initialized just like the default framebuffer for any WebGL interface:
This example gets the XRWebGLLayer for a session and then passes its framebuffer into the WebGL context's bindFramebuffer() function.
let glLayer = xrSession.renderState.baseLayer;
gl.bindFramebuffer(gl.FRAMEBUFFER, glLayer.framebuffer);