POV-Ray : Newsgroups : povray.newusers : How can I make an object generate light in a radiosity scene? : Re: How can I make an object generate light in a radiosity scene? Server Time
30 Jul 2024 16:27:38 EDT (-0400)
  Re: How can I make an object generate light in a radiosity scene?  
From: incognito
Date: 27 Nov 2003 19:45:01
Message: <web.3fc69a25b2b1540cca01221d0@news.povray.org>
Christopher James Huff wrote:
>In article <web.3fc64abeb2b1540c240f43310[at]news.povray.org>,
> "incognito" <nomail[at]nomail> wrote:
>
>> The interesting thing is I asked the prof if he wanted us to have pure
>> radiosity or radiosity with conventional light sources a week ago and he
>> replied he wanted pure radiosity with one object generating light (a sun)
>> and also a light source that would act as the sky...so that is what I have
>> been trying to do.
>
>You sure he said to do that? The usual arrangement has things the other
>way around. Light sources, even area lights, are very bad at doing
>diffuse light coming from large areas, such as a sky. Radiosity is very
>bad at doing light coming from more or less a single point. Radiosity
>for the sky and an area light for the sun would make much more sense.
>And if he said to use a light source, it wasn't pure radiosity.
>
If it clarifies any, here is the assignment:

http://www.evl.uic.edu/aej/488/fall2k3.hw4.html

>
>> So far, I believe I have the sky ok but not sure if the
>> object light is working correctly (i.e. doesn't seem like the objects
>> nearer to the sun object are lit up any more than those further away (which
>> I take to be how it *should* work).
>
>Try removing all light sources...your radiosity lighting may simply be
>too dim.
>

I just did this and it was not too dim. I think it does seem to be acting as
a light source now just maybe not very noticeable because I do have a
relatively light background. (My background ambient is set to only 0.4 and
the sun is set to ambient 1). I will go ahead and try the diffuse at a
higher value too since I would like it to be more noticeable.

Thanks.
>
>> From what you are saying below, sounds like I do not need to set the diffuse
>> vals of the other objects (just ambient to 0 and translate x), am I
>> understanding that correctly?
>
>You only need to adjust the diffuse value if the default of 0.6 doesn't
>suit your needs. I generally set the default ambient to 0 and the
>default diffuse to 1 (and put a dim, shadowless light at the camera
>position to fill in shadows).
>
>Christopher James Huff <cja### [at] earthlinknet>
>http://home.earthlink.net/~cjameshuff/
>POV-Ray TAG: chr### [at] tagpovrayorg
>http://tag.povray.org/
>


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.