This image has been rendered using the POVRay raytracer. I created the original scene file in 1998. More than ten years later I made a few improvements to it, and rendered it again at a much higher resolution. No post-processing has taken place on the image to make the illusion work; this is the 3D scene as it is rendered by the raytracer. "How can this be?" you may wonder. That's a good question indeed.