Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!bcstec!yak!tpd6908
From: tpd6908@yak.COM (Tom Dickens)
Newsgroups: comp.graphics
Subject: RGB color mixing/averaging
Keywords: RGB, super-sampling, transparency
Message-ID: <173@yak.COM>
Date: 14 Mar 90 19:14:25 GMT
Organization: Boeing Computer Services, Seattle
Lines: 21

I am looking for a simple routine that will take 2 rgb values, a ratio
for mixing them (ie. 0.5), and will return the resulting rgb value.
This is desired for determining a pixel color after super-sampling, or when
combining colors while working with transparent surfaces.

The problem I have is I expect the resulting rgb value to follow 
'real world' results.  (ie. case1: red+blue=purple, case2: blue+yellow=green)
Case1 works in rgb space, but case2 does not.  I have read multiple
articles on the subject and have experimented with converting to HSV,
CMY, HLS spaces, linearly mixing, then converting back, but have not
gotten satisfactory results.  I have an appreaciation for the physical
aspects of light and properties of different materials etc., but what I
need is a quick and simple method that works as expected.  I am in the
process of deriving such a method since I have not found any papers
which address this.  

Any information, references, code samples, or other ideas would be more
than welcome.
Thanks in advance.   Tom Dickens, Areodynamic Research
		     Boeing Computer Services
		     (206) 865-6122