WebGL Stencil Masks a Cube
Swipe Over the Canvas to Move the Cube
This Web page demonstrates use of a WebGL stencil. See a portion of the background graphic, where a stencil masks part of the cube.
Each side of the cube is texture mapped with a different color. A large quad renders behind the cube. A small stationary square stencil in the center of the canvas masks off the cube, as the cube passes over the stencil area. See a portion of the background quad through the cube, where the stencil masks the cube.