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4 Nov 2024 12:59:31 EST (-0500)
  distant light sources (Message 1 to 4 of 4)  
From: Slashdolt
Subject: distant light sources
Date: 3 Feb 2003 09:02:32
Message: <3e3e7678@news.povray.org>
I'm creating an outdoor scene, and since most of my scene is fairly close to
the camera, I've been using "inches" as the unit of scale.  However, I
started to add some minor features to the background and wanted to have them
about 200 yards/meters away and still have them be visible (that's 200*3*12
units), so I backed up my "sun" to about 10 miles away (10*5280*12 units).
My render became incredibly slow, and I've noticed that the shadows have
almost disappeared (using radiosity).  Does something happen to very distant
light sources that causes this?  Are my numbers getting too big or
something?

I'm using a point light source, focal blur, and radiosity.  Other than that,
I don't have any strange settings.

Should I simply alter the scale of my objects and make my "sun" fewer units
away?  I suppose I can experiment with these things, but my current render
was taking about 10 hours (putting my light source 1 mile away appears to
make it about 20 hours), so it's pretty time-consuming for trial and error.

I looked in the manual, and did a couple ng searches, but I didn't turn up
anything related to this.  I suppose there is also a chance that I
inadvertently changed something else in my scene file, but I don't think I
did...

--
Slash


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From: Slashdolt
Subject: Re: distant light sources
Date: 3 Feb 2003 09:55:28
Message: <3e3e82e0$1@news.povray.org>
I'm actually not sure what's going on at this point.  I've done some simple
tests and I'm not getting the slowness and washed-out-shadows effect no
matter where I place my objects and how many units away the light source
is...

I'm going to go back to an earlier version and see what I can find out...


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From: Slashdolt
Subject: Re: distant light sources
Date: 3 Feb 2003 14:13:38
Message: <3e3ebf62@news.povray.org>
It definitely seems to be something funny with the point light source and
making it farther away.  I'm not sure why I can't duplicate the slowness
with a simple scene, though.  Anyway, I switched to using a parallel light
source, which probably makes more sense anway, and it's fast.

Replying (again) to my own post...  I need a life...

Slash


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From: Ross Litscher
Subject: Re: distant light sources
Date: 6 Feb 2003 16:28:43
Message: <3e42d38b$1@news.povray.org>
have you played with the fade_distance and fade_power? don't know if that
would cause slowness at far away distances, but maybe it does.

Slashdolt <jer### [at] questsoftwarecom> wrote in message
news:3e3ebf62@news.povray.org...
> It definitely seems to be something funny with the point light source and
> making it farther away.  I'm not sure why I can't duplicate the slowness
> with a simple scene, though.  Anyway, I switched to using a parallel light
> source, which probably makes more sense anway, and it's fast.
>
> Replying (again) to my own post...  I need a life...
>
> Slash
>
>
>


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