Steve Baker (steve++at++mred.bgm.link.com)
Fri, 24 Jan 97 08:07:14 -0500
> You have hit a problem that I have seen in everything from flight
> simulators to animation systems, ie. lights/color values are clamped to 1.0.
>
> So here is my open wish list:
>
> 1) Allow values greater than 1.0 to be input and used in the
> computation. After all, even a dark grey surface will look white if you
> pump enough light into it.
Woaaa - be very careful what you wish for. Suppose they did compute
things the way you suggest. What would happen to a red surface with
RGB values like (1.0,0.1,0.1) - presuming that the colour calculations
are done indepenantly in RED, GREEN and BLUE - what would happen? The
answer is that all three colour components could go over 1.0 and (presumably)
be clamped to 1.0 for display. This would mean that the predominantly red
surface would show up as white - but real-world diffuse reflectors don't
change colours like that. (Don't get confused with specular reflectors -
which are a different matter).
> 2) Give me 10/12 bit DACs on the IR. Then I can render a moon lit night
> scene with values below 128 (or 0.5) but still "spike" the display with
> values over 3000 for light sources.
Building DAC's with high precision *and* high speed is a non-trivial problem.
There is a real problem with lighting - and some fixes could be attempted,
but you have to be really careful. One obvious area is penetration through
fog - really bright lights should show through fog better than they do
right now, for example.
Steve Baker 817-619-1361 (Vox-Lab)
Hughes Training Inc. 817-619-8776 (Vox-Office/Vox-Mail)
2200 Arlington Downs Road 817-619-4028 (Fax)
Arlington, Texas. TX 76005-6171 Steve++at++MrEd.bgm.link.com (eMail)
http://www.hti.com (external) http://MrEd.bgm.link.com/staff/steve (intranet)
http://web2.airmail.net/sjbaker1 (external)
"You can't destroy the Earth - that's where I keep all my stuff!" - The Tick.
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