Dynamic Cubemap Demo
This demo shows a perfectly reflective object surrounded by a skybox and 21 moving cubes. You have to turn on animation for the cubes to move, of course. Initially, all the cubes are lined up behind the teapot.
The cubemap texture used for the reflection map is not the same as the texture for the skybox, since the reflection map texture has to include the moving cubes. All six faces of the reflection cubemap are redrawn for each frame of the animation.
You can drag on the image to rotate the entire scene. (You might be able to rotate the reflective object with the left and right arrow keys, if keyboard input can be directed to the demo.)
This demo is essentially a copy of the sample WebGL program cube-camera.html.