Sorry if this isn't exactly the right place for
a question, but I've a couple of pictures to post
to support it.

I've been working on a texture for tree bark. With
conventional lighting and no radiosity it looks
pretty much ok in my opinion (norad.jpg), but when
I try it out in my scene, with radiosity and very
little conventional light it looks very different
and substantially worse (rad.jpg).
I have normal on and recursion_limit 2 in the
radiosity block, the texture itself is at
http://thyme.homelinux.net/Bark.inc.html
if it's relevant.

-- 
Bill Hails
http://thyme.homelinux.net/

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Attachments:
Download 'norad.jpg' (11 KB) Download 'rad.jpg' (9 KB)

Preview of image 'norad.jpg'

Preview of image 'rad.jpg'

Try to avoid any ambient values in texture, unless you deliberately want to
use ambient parts of the scene for lighting purposes.

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news:40d73138@news.povray.org...
> I've been working on a texture for tree bark. With
> conventional lighting and no radiosity it looks
> pretty much ok in my opinion (norad.jpg), but when
> I try it out in my scene, with radiosity and very
> little conventional light it looks very different
> and substantially worse (rad.jpg).

Radiosity isn't very gentle on small normals and doesn't give highlights, so
a bumpy map with almost rad-only lighting looks typically flat.
In a sunlit outdoor scene, using normal conventional lighting and radiosity
at the same time works pretty well and is relatively easy to set up. You get
the best of both worlds with these scenes: deep shadows, bright highlights
and perfect radiosity "bleeding".
Cloudy outdoor scenes relying mostly on radiosity are a little bit trickier,
particularly on natural objects with complex textures. Light_groups may come
handy for adding some shadows and hightlights in those cases.

G.

-- 
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Gilles Tran wrote:


> news:40d73138@news.povray.org...
>> I've been working on a texture for tree bark. With
>> conventional lighting and no radiosity it looks
>> pretty much ok in my opinion (norad.jpg), but when
>> I try it out in my scene, with radiosity and very
>> little conventional light it looks very different
>> and substantially worse (rad.jpg).
> 
> Radiosity isn't very gentle on small normals and doesn't give highlights,
> so a bumpy map with almost rad-only lighting looks typically flat.
> In a sunlit outdoor scene, using normal conventional lighting and
> radiosity at the same time works pretty well and is relatively easy to set
> up. You get the best of both worlds with these scenes: deep shadows,
> bright highlights and perfect radiosity "bleeding".
> Cloudy outdoor scenes relying mostly on radiosity are a little bit
> trickier, particularly on natural objects with complex textures.
> Light_groups may come handy for adding some shadows and hightlights in
> those cases.
> 
> G.
> 

Thanks for the insight. I'm trying now with a light group after
dropping the diffuse setting on the texture quite a bit. I'll
swap in an area light if it's looking good.

-- 
Bill Hails
http://thyme.homelinux.net/

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Apache wrote:

> Try to avoid any ambient values in texture, unless you deliberately want
> to use ambient parts of the scene for lighting purposes.

Yes, thanks, I already have ambient 0 for that texture. However
I'm puzzled as to why the red/brown center pigment of the smooth
part of the texture is that much more prominent with radiosity
turned on?
In any case I've re-ordered the pigment map to avoid that artefact.

-- 
Bill Hails
http://thyme.homelinux.net/

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