POV-Ray : Newsgroups : povray.general : Possible atmospheric solution? : Possible atmospheric solution? Server Time
12 Aug 2024 07:17:26 EDT (-0400)
  Possible atmospheric solution?  
From: Andrew Cocker
Date: 7 Mar 1999 18:57:58
Message: <36e31286.0@news.povray.org>
I just had an idea. See what you think. There has been much discussion in this group
regarding media and it's shortcomings, particularly with regard to creating a dusty /
smoky atmosphere. This is what I use it for mainly, but usually give up because a) it
takes so long to render, and b) because it often / usually looks too grainy.
My idea is this. Would it not be effective to use similar code to the way that
constant
fog works ( which seems to just change each pixel by a certain amount towards the
chosen
fog colour ), but *only for those pixels that are in line of sight of a light source*.
So
any obstructions would effectively seem to be casting a shadow *onto* the fog. It
seems to
me that this is how a dusty atmosphere looks when light shines in through a window
etc. Of
course the huge benefit of this approach would be a minimal increase in rendering
time.
You could have a parameter for controlling the intensity of the effect ie how near to
white each pixel becomes, a parameter to control how the effect fades as it moves
further
from the light source. I'm not sure how additional lights would affect things..they
could
each add to the intensity where spotlights cross one another, or they could all be
automatically adjusted so an overall effect is maintained, regardless of the number of
lights used.
Finally, the fog could be affected by, for example, a pigment map in a similar way to
a
density map, so that wherever rgbf 1 occured, the fog was clear. This could then be
animated in the usual way to create many atmospheric conditions. Sort of a simpler
Density.

Have I overlooked something here? My idea seems so simple, but sometimes the simple
ideas
work best. I'm not suggesting getting rid of media, as it excels at fires, clouds etc,
but
in my opinion it's overkill in some instances.

Maybe for the next version?

-----------
Andy


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