POV-Ray : Newsgroups : povray.general : looks like and atmosphere.... Server Time
16 Nov 2024 17:23:05 EST (-0500)
  looks like and atmosphere.... (Message 1 to 3 of 3)  
From: Jeffry J  Brickley
Subject: looks like and atmosphere....
Date: 3 Jun 1998 14:35:42
Message: <3575977C.8D97A7EC@geocities.com>
I've got a lightning include file and I am working onadding
atmospheric lighting effects, but I've run into a few problems....  I
first tried rendering a light source at every bend of the lightning....
This resulted in approximately 250 light sources,  although rendering
slowly, the light sources stopped interacting with the atmosphere after
about 50-60 lights (I never calculated it exactly as I moved on to try
other things)....  Then I tried reducing the number of lights to every
3rd or 4th bend and only on the main branch which resulted in good
lighting effects in the atmosphere, but an odd "layered" look at
eye-level....  Then I tried the "looks_like" in the light definition and
tried to use the entire bolt as a a light and the atmospheric effects
turned off all together.....  Anyone have any idea how to bypass these
problems? (I'm using 3.04POVray for Windows95)
just me,
    jeff

`._`.*.'_._ ____.____   Jeffry J. Brickley
* .o   o.* `.`. +.    . jbr### [at] geocitiescom
`  |\^/|  `. * .  * ` Magic is REAL, unless declared INTEGER.
`.. \U/ . + http://www.geocities.com/CapeCanaveral/Hangar/9078/
`.  /_\  .`. http://www.geocities.com/SiliconValley/Pines/3210


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From: Robert Dawson
Subject: Re: looks like and atmosphere....
Date: 4 Jun 1998 10:19:31
Message: <01bd8fc4$f2dec690$1c8eb88c@rdawson>
Jeffry J. Brickley <bri### [at] geocitiescom> wrote in article
<3575977C.8D97A7EC@geocities.com>...
>     I've got a lightning include file and I am working onadding
> atmospheric lighting effects, but I've run into a few problems....  I
> first tried rendering a light source at every bend of the lightning....
> This resulted in approximately 250 light sources,  although rendering
> slowly, the light sources stopped interacting with the atmosphere after
> about 50-60 lights (I never calculated it exactly as I moved on to try
> other things)....  Then I tried reducing the number of lights to every
> 3rd or 4th bend and only on the main branch which resulted in good
> lighting effects in the atmosphere, but an odd "layered" look at
> eye-level....  Then I tried the "looks_like" in the light definition and
> tried to use the entire bolt as a a light and the atmospheric effects
> turned off all together.....  Anyone have any idea how to bypass these
> problems? 

	Looks_like does not solve your problem. It does not make the entire object
into a light - it just prevents that one object from blocking the light or
being illuminated by it. 

	Unless you want the lighting to work properly with a pinhole camera or
other simulated optics, you need nowhere near that many lights. If you use
(say) a 10x1 area light with "adaptive" and "jitter" turned on, lined up
approximately
with your lightning bolt, you will probably not be able to see the
difference and it will run very fast, compared with even a 50-light array. 

	Your "layered" look is not because of too few lights, I suspect, though
using a lot of them might cure the problem at a mighty cost. Rather it is
likely to be because of not having your atmosphere parameters set
optimally. Try using jitter, adaptive, and antialiasing here, too.

		-Robert Dawson


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From: Matthew Bennett
Subject: Re: looks like and atmosphere....
Date: 4 Jun 1998 14:00:49
Message: <01bd8fe2$bbfc58e0$4e3563c3@mrbcomp>
If you do manage to get it working (hopefully the above post will help...)
then please feel free to stick a sample image up on the www; your
lightning-in-atmosphere idea sounds great :)

Matt


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