POV-Ray : Newsgroups : povray.newusers : Background and area light : Re: Background and area light Server Time
1 Jul 2022 19:14:48 EDT (-0400)
  Re: Background and area light  
From: omniverse
Date: 30 Dec 2016 01:55:01
Message: <web.586604733800872e9c5d6c810@news.povray.org>
"PerroNoob" <ara### [at] gmailcom> wrote:
> I'm trying to render a long rectangle (with some extra stuff) using an area
> light. The problem is that I always see a dark background, even if I extend the
> area light further along the z direction. If I change the perspective, I also
> see that extending the area light region does not have much effect, there is
> always a darker side on the rectangle, which I don't know why. I've also tried
> increasing the height (y direction) of the area light with a better result,
> however the shadows are smaller in that case.
>
> What I want is to make most of the floor and background as white as possible but
> without making the rectangle to look too bright (that's why I use a gray
> background).
>
> The code is here (I'm using the rc3metal files; btw, is there a way to make the
> Bronze rectangles even more realistic? do I need a turbulence or something like
> that?) :

There isn't anything for the metal to reflect so that's why it appears
featureless, it's only reflecting the background gray. A normal, such as
granite, would make it less flat but possibly grainy or wavy depending on scale
of that.

I rendered your scene using a large sphere, instead of background color, putting
an image_map of a room picture in it. That gave it something to reflect. Depends
on what your wanting it to be like. I also tried just a pigment pattern and that
might not be able to produce a discernable reflection object. In other words,
could lack a perceived reflection from external source unless you can also see
that elsewhere (from behind, above, wherever).
A "room" reflected in the metal probably doesn't need to be seen to know it's
from the surroundings.

The ground plane might be able to use something like:

    finish{ambient 0 diffuse 0.1 specular 0.9 roughness 9}

Maybe extreme but this would even out the brightness and still leave a shadow,
versus using emission 0.5 for example which would affect that shadow.

Bob


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