EMAIL:  bsewell@usit.net
NAME:  Bob Sewell
TOPIC:  Math & Physics
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
TITLE:  Elementary Spectral Analysis  (bs-esa.jpg)
COUNTRY:  USA
WEBPAGE:  http://www.public.usit.net/bsewell/index.html
RENDERER USED:  PovRay 3.1 for Windows 32-bit
TOOLS USED:  Calculator, Photoshop 2.5 LE (for title and TGA>JPG conversion)
RENDER TIME:  1 hr, 55 min, 58 sec
HARDWARE USED:  AT&T Globalyst 630 (P133 w/64MB RAM)

IMAGE DESCRIPTION:  Light through a simple prism.  Good thing I'm not entering to win, 'cause I don't have the talent nor the time to seriously compete here!  I'm only after suggestions for improvement.  Anyway, this is just an experiment which builds upon my previous exercises with light through a prism.  

DESCRIPTION OF HOW THIS IMAGE WAS CREATED:  All objects were built by hand, which was simple to do with such simple objects.  The walls and floor are simple polygons, the flashlight a union of a cylinder with the intersection of a box and an elongated sphere, plus the switch, a box with a row of about 9 cylinders offset to dip into the switch body for an "easy grip."  The prism is a box rotated 45 degrees with another box subtracted from a diagonal half.  All textures are Povray standard issue textures, with one exception.  The prism glass I had to fiddle with a bit to get it to reflect some of the light back to the camera.  All I did was take the T_Glass2 texture and change the rgbf to rgbt, thereby transmitting the white color that T_Glass2 was filtering.

The spectrum is a row of six spotlights with the same originating point but six "point ats" which differ by a half a unit, each new color creeping further up the wall than the last.  The lights were colored, in order, red, orange, yellow, green, blue, violet.

I'm getting frustrated with the spotlight aspect, because I can't seem to get it to reflect off glass the same way a point light does, which is why I had to adjust the glass' texture.  I'm sure it's me, but I can't seem to get the hang of aiming it correctly, and if I assign the spotlight as part of an object (such as inside the parabola of a flashlight) all rules for positioning the thing seem to fly out the window... nothing makes sense.  Oh well, practice, practice...