because it was recommended in the docs (3.1 or mega, i can't recall
which) that when using radiosity one should not have ambient objects, i
try to develop all of my textures with this in mind.  in a cursory
examination of the metals available in both pov and moray, i found that
all of them had an ambient value.  so the question is how does one make
metal without it?  does anyone have some examples, great or small, that
you wouldn't mind sharing?

and for anyone interested, i just made a single pov-only texture for the
blue on r2d2's "head".  it renders just as fast as anything else, but
you should see the listing.  using "proper" indentation and line usage
it would print to at least 3 pages long i think.  i've got a couple more
head items to model tonight and i'll start on the body tomorrow.  unlike
my xwing, not everything will animate; only the head, the holo-projector
things, the legs and the third leg.  that'll be version 1.  and i still
wasn't able to find a completely front-on view.  i have one, but his
head is turned a little.  i'd like it centered so i can get his 'eye
box' angles right.  i also have a 'drawing' but i'm sure you all know
how accurate that can be.

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ryan constantine <rco### [at] yahoocom> wrote:
: because it was recommended in the docs (3.1 or mega, i can't recall
: which) that when using radiosity one should not have ambient objects, i
: try to develop all of my textures with this in mind.

  Precisely in megapov. If you set ambient to 0 in povray 3.1, you will get
no radiosity at all. This has been changed in megapov.

:  in a cursory
: examination of the metals available in both pov and moray, i found that
: all of them had an ambient value.  so the question is how does one make
: metal without it?

  Just removing the ambient value perhaps?

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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ryan constantine wrote:
> 
...
> examination of the metals available in both pov and moray, i found that
> all of them had an ambient value.  so the question is how does one make
> metal without it?

If you want no ambient light in all the scene, just use ambient_light
0.0 in your global_settings statement.

Bouf.

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"ryan constantine" <rco### [at] yahoocom> wrote in message
news:3976BA97.A450157C@yahoo.com...
| because it was recommended in the docs (3.1 or mega, i can't recall
| which) that when using radiosity one should not have ambient objects.
|  so the question is how does one make metal without it?

I've used something like ambient_light 0.2 along with assumed_gamma 3 so
that I don't lose all aspects of the original ambience.  Trick is to keep
the ambient very low when doing MegaPov radiosity.  Either that or you might
have to raise all the diffuse values.  I'm sure it's been asked before about
how it might benefit to have a global diffuse also, and with this "new"
radiosity I think it is needed more than ever.  Not that I know if that
would be appropriate to do.

Bob

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> :  in a cursory
> : examination of the metals available in both pov and moray, i found that
> : all of them had an ambient value.  so the question is how does one make
> : metal without it?
> 
>   Just removing the ambient value perhaps?
 of course i tried that, but (naturally) they get really dark.  so i
guess more precisely i want to know how to compensate for the darkness.

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does this effectively eliminate all ambient items in textures?  or does
it do something else?  and if it does eliminate the ambient parts of
textures, the textures will be darker, so how do i conpensate?  or
should radiosity compensate for me?

Christophe Bouffartigue wrote:
> 
> ryan constantine wrote:
> >
> ...
> > examination of the metals available in both pov and moray, i found that
> > all of them had an ambient value.  so the question is how does one make
> > metal without it?
> 
> If you want no ambient light in all the scene, just use ambient_light
> 0.0 in your global_settings statement.
> 
> Bouf.

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"ryan constantine" <rco### [at] yahoocom> wrote in message
news:397### [at] yahoocom...
> does this effectively eliminate all ambient items in textures?  or does
> it do something else?  and if it does eliminate the ambient parts of
> textures, the textures will be darker, so how do i conpensate?  or
> should radiosity compensate for me?

the global ambient acts as a multiplyer for local ambients, so setting it to
0 will eliminate all ambients (the default is presumably 1).

Radiosity should compensate - essentially, ambient is faked radiosity
(IMHO).

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ryan constantine wrote:
> 
> does this effectively eliminate all ambient items in textures?  or does
> it do something else?  and if it does eliminate the ambient parts of
> textures, the textures will be darker, so how do i conpensate?  or
> should radiosity compensate for me?

It modify all the ambient in all textures like this:

final_ambient = finish_ambient * ambient_light.

When using radiosity, I generally use ambient_light 0.2 or 0.3 to lower
the impact of ambient light (which is a *very* rough and inaccurate form
of radiosity...).


Bouf.

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Use assumed_gamma 1.0 and whatever is correct Display_Gamma
for your system in povray.ini. When removing the static ambient
light it is important to set gamma correctly so that radiosity
can produce correct ambient level. See
news://news.povray.org/39423CFE.5565DBF%40kivisalo.net
news://news.povray.org/39450341.610E8FC3%40kivisalo.net


K.K.

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thanks for the tips.  is there a default assumed_gamma?  the reason i
ask is because in moray, the assumed_gamma box actually outputs the same
number for both the display_gamma setting in the ini file and the
assumed_gamma in the pov file.  i'm not sure how to fix this.  of
course, i could always just open the exported file in megapov itself and
this is what i'll do if there is no way of dealing with it in moray
itself.  thanks again. 

Kari Kivisalo wrote:
> 
> Use assumed_gamma 1.0 and whatever is correct Display_Gamma
> for your system in povray.ini. When removing the static ambient
> light it is important to set gamma correctly so that radiosity
> can produce correct ambient level. See
> news://news.povray.org/39423CFE.5565DBF%40kivisalo.net
> news://news.povray.org/39450341.610E8FC3%40kivisalo.net
> 
> K.K.

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