TITLE: Snowflake Factory NAME: Mitch Richling COUNTRY: USA EMAIL: richmit@member.ams.org WEBPAGE: http://hardwoodproduct.airweb.net/personal/richmit/index.htmlJPGFILE: mjr_win1.jpg ZIPFILE: mjr_win1.zip TOPIC: winter COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: mjr_win1.jpg ZIPFILE: mjr_win1.zip RENDERER USED: Povray 3.1.g TOOLS USED: Emacs, Povray, Photoshop, MacOS X RENDER TIME: 286 seconds HARDWARE USED: 800MHz G4, 1GB RAM IMAGE DESCRIPTION: What is the secret of this image? The secret is that only four spheres, 3 triangles, and 1 plane make up this image. No textures, no colors (except white), no bump maps, no normal maps, no bit maps, no turbulence -- just simple reflection. That's right, the complexity of the image is due 100% to simple reflection off of four smooth, shiny spheres and four smooth, flat, shiny objects. This image really exhibits the reason we use ray tracers -- they TRACE RAYS. :) Much of the beauty of a snowflake is derived from light reflecting off of, and refracting through, a very simple substance with virtually no color of it's own. I appreciate the fact that this image's beauty is completely derived from reflection. DESCRIPTION OF HOW THIS IMAGE WAS CREATED: Four spheres of radius 2 are placed so that each sphere touches every other sphere, but so that no two spheres intersect in more than one point. Each sphere is a perfect mirror. The centers of the spheres will be at the vertexes of a regular tetrahedron. Three faces of the tetrahedron are then constructed out of three triangles that are white and highly reflective. Finally a white, highly reflective, plane is placed above the construction parallel to the missing side of the tetrahedron. Light sources are placed between the plane and the spheres and so is the camera. The camera is pointing directly at the back-most sphere, through the missing face of the tetrahedron. The image is then formed from the reflections of the three triangles and the plane. This is why the triangles and plane can not be perfect mirrors. If they were, no image would be formed! The image will have interesting fractical properties if the faces of the tetrahedron have color. Very striking images, that make the snowflake image appear dull, can be obtained when some color is added to the mix. For examples of such images, see my web page. The Povray input file that generated this image is included in the submission... all 31 lines of it. :)