Path: utzoo!dciem!king
From: king@dciem.UUCP (Stephen King)
Newsgroups: comp.graphics
Subject: Re: Ray Tracing Jell-O Brand Gelatin
Message-ID: <2690@dciem.UUCP>
Date: 9 Mar 88 18:05:53 GMT
Article-I.D.: dciem.2690
Posted: Wed Mar  9 13:05:53 1988
References: <20312@bu-cs.BU.EDU> <23187@ucbvax.BERKELEY.EDU>
Reply-To: king@dciem.UUCP (Stephen King)
Organization: D.C.I.E.M., Toronto, Canada
Lines: 50
Summary: 

In article <23187@ucbvax.BERKELEY.EDU> ph@degas.Berkeley.EDU.UUCP (Paul Heckbert) writes:
>In article <20312@bu-cs.BU.EDU> madd@.UUCP (Jim Frost) writes:
>>RAY TRACING JELL-O BRAND GELATIN
>>...
>
>Please get this garbage off the net!  We're carrying on a serious technical
>discussion here and we don't need this sort of facetious drivel tying up the

*****FLAME ON***
Go soak your head. I got a real laugh out of the referenced posting and I
resent you making yourself out to be some net-god with comments like those
above. Rendering substances such as Jello creates problems which have real-
world significance. A light hearted, even outlandish, approach can stimulate
thought and sometimes leads to novel solutions.
*****FLAME OFF***

>    (1) Does anyone have an implementation of GKS for the EGA board
>	in 8008 assembler?
           ^^^^ 8088 assumed. Why spend so much effort on a machine with
such miserable graphics performance? Get a REAL graphics engine instead.

>    (2) I just bought an Apple II and I want to know how to
>	get NTSC video out of it so I can make great films like Luxo Jr.

You will never get Luxo Jr. quality with this approach. NTSC resolution is
too low (you need AT LEAST 1k x 1k resolution, preferrable 2k x 2k or even
4k x 4k, available from Dicomed film recorders etc.) Furthermore, the Apple
would probably take a great deal of time to render a single frame. For the
sake of argument, let's say 24 hours per frame (it may be 2x or 3x this).
At motion picture frame rate (24fps), that's 24 days to render one second
of playback time. Thus, a fifteen second short would require almost a year
of constant computing to produce. Hardly worth the effort.

>    (3) What's the formula to convert RGB to luminance?

	E'y = 0.30E'r + 0.59E'g + 0.11E'b

	E' denote gamma-corrected signals
	y represents luminance
	r - red, g - green, b - blue

>	I've been using sin(R)+atanh(G)*log(B), but I'm getting strange results.

	No wonder.

-- 
    * Defence & Civil Institute *    {decvax|ihnp4|watmath}!utzoo!dciem!king 
    * of Environmental Medicine *          or    uwbeaver!utcsri!dciem!king
   - Simulation & Training Group -         or    uunet!mnetor!dciem!king
(may or may not endorse my opinions)       or    dciem!king@zorac.arpa