The VRLayer interface (dictionary) of the WebVR API represents a content layer (an HTMLCanvasElement or OffscreenCanvas) that you want to present in a VR HMD.
The leftBounds read-only property of the VRLayer interface (dictionary) defines the left texture bounds of the canvas whose contents will be presented by the VRDisplay.
The rightBounds read-only property of the VRLayer interface (dictionary) defines the right texture bounds of the canvas whose contents will be presented by the VRDisplay.
The source read-only property of the VRLayer interface (dictionary) defines the canvas whose contents will be presented by the VRDisplay.