markley@celece.ucsd.edu (05/23/89)
I am in the process of learning about raytracing and rendering and I have determined that I am really lost on determining good RGB values. Does anyone have a list of RGB values for different materials and surfaces? I would really like metallic values if possible. Please email responses to me directly if possible and I will post a composite of what I get. Thanks, Mike Markley University of California,San Diego markley@celece.ucsd.edu markley@kubrick.ucsd.edu
jlg@hpfcdq.HP.COM (Jeff Gerckens) (05/26/89)
The rgb values will be different for almost every monitor that you may care to look at and different again if you have the option of gamma correction in your hardware. The most correct solution is to use a colorimeter to determine the color of your phosphors, the ambient light, and a sample of the metal in question and apply colorimetric priciples to determine the correct rgb values for your viewing situation. The most practicable solution is to write a small program that lets you adjust rgb values while watching the colors change on the screen so you can choose the color that looks best to you. There was an article last year in TOG concerning which color spaces to use as control for the second option. Some allow for quick convwrgence to something close to hat you want, while others allow for more accuracy once you get near the desired color. Color is word that is bandied about by most CS folk with little knowledge of what is really involved. - Jeff Gerckens Hewlett-Packard Graphics Technology Division (jlg%hpfcrg@hplabs.hp.com)