uselton@nas.nasa.gov (Samuel P. Uselton) (12/01/90)
In article <21498@well.sf.ca.us> Jef Poskanzer <jef@well.sf.ca.us> writes: >In the referenced message, musgrave-forest@cs.yale.edu (F. Ken Musgrave) wrote: >} I can provide you with an image of a prism, but not ala Pink Floyd. >}For technical reasons peculiar to computer graphics, that image would >}be VERY hard to do (as a physical simulation). > >That's funny, cause I have a print of a Floydish prism done by III in >the late '70s... >--- >Jef > I know the triple I (III) prism picture shown at SIGGRAPH (and in the slide set) and it is OBVIOUSLY not physically correct. The spectrum changes as if wavelength were a function of distance from the prism! That is, one end of the color spectrum is adjacent to the (exit face of the) prism and the colors transition to the other end of the spectrum as the diverging beam nears the right edge of the frame of the picture. I used to use it in class to make the point about looking carefully at "pretty" images that may not be what they seem. Sam Uselton ex-prof uselton@nas.nasa.gov employed by CSC working for NASA speaking for myself