A single object in the center of the scene is textured with the reflection/refraction maps while a number of objects rotate around it. A skybox is also being rendered to show the environment reflection.
The scene is rendered 6 times from the object’s perspective to generate the environment maps. When the reflective object is being rendered, each pixel on the object tests a ray from the camera’s position to the pixel and reflected across its normal to calculated texture coordinates that are used to sample the environment maps. The only difference between reflection and refraction is the way this ray is reflected to calculated the texture coordinates.