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From: Orchid XP
Subject: Saturation
Date: 22 Apr 2005 17:11:59
Message: <4269689f$1@news.povray.org>
OK, take a quick look at this:

http://www.wallpaper.net.au/wallpaper/abstract/Abstract%20Car%20Alpha%20-%201024x768.jpg

So, it's a reflective car. But how do they make it *look* reflective?? I 
mean, it doesn't take much to tell POV-Ray "please compute reflectiosn". 
But that, alone, doesn't make the thing *look* reflective. I've tried 
all sorts of things... but no matter what I scatter around the place to 
reflect off things, they just don't look very reflective. :-(

Also, take a look at

http://www.pixar.com/featurefilms/abl/

OK, so it's a picture of some cartoon characters. And not terribly 
interesting ones. But look at the image itself. It's sharp and crisp, 
but most of all, it looks lushously saturated. How do you *do* that? I 
can never seem to get the lighting right...

Similarly, check this out:

http://www.finalfantasy-spiritwithin.com/www/image14.htm

OK, those clouds would probably give POV-Ray a real headache, but how do 
they get the colours so good? Maybe I just suck at this...


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From: Tim Nikias
Subject: Re: Saturation
Date: 22 Apr 2005 18:20:16
Message: <426978a0$1@news.povray.org>
Reflection: depends on the reflectivity and what you reflect, eh?

Pixar: Bright, saturated colors. And ever heard of lightgroups? Useful for a
lot of added light which won't affect other objects. I've used it in my
latest image "The Dreamer" to create a silhouette-type light on the
character in the scene.

Final Fantasy Skies: Ever heard of matte paintings?

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>


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From: Orchid XP
Subject: Re: Saturation
Date: 23 Apr 2005 05:05:01
Message: <426a0fbd@news.povray.org>
> Pixar: Bright, saturated colors. And ever heard of lightgroups?

Yes.

Is that how they manage it then? My disregarding the laws of physics? 
Strange - I would have expected that to look wrong...

> Final Fantasy Skies: Ever heard of matte paintings?

No.


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From: Tim Nikias
Subject: Re: Saturation
Date: 23 Apr 2005 05:20:41
Message: <426a1369@news.povray.org>
> Is that how they manage it then? My disregarding the laws of physics?
> Strange - I would have expected that to look wrong...

It depends on how you do it. Also, I would guess that the Composite Artist
has a hand in tweaking the colors for saturation.

> > Final Fantasy Skies: Ever heard of matte paintings?
>
> No.

Matte Paintings are hand-drawn (either real or digital) paintings which you
place behind the filmed objects, often used via digital compositing and
green/blue-screen these days. They can be animated or even have parallax
effects, depending on the technique used, but it's basically a painting
instead of real geometry.

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>


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From: Orchid XP
Subject: Re: Saturation
Date: 23 Apr 2005 05:26:24
Message: <426a14c0$1@news.povray.org>
>>Is that how they manage it then? My disregarding the laws of physics?
>>Strange - I would have expected that to look wrong...
> 
> It depends on how you do it. Also, I would guess that the Composite Artist
> has a hand in tweaking the colors for saturation.

OK. Cos, one of the major problems I constantly have with POV-Ray is the 
image is too dark, or it's too light, or it looks washed out, or part of 
it is too bright but the rest is too dark, or......

>>>Final Fantasy Skies: Ever heard of matte paintings?
>>
>>No.
> 
> 
> Matte Paintings are hand-drawn (either real or digital) paintings which you
> place behind the filmed objects, often used via digital compositing and
> green/blue-screen these days. They can be animated or even have parallax
> effects, depending on the technique used, but it's basically a painting
> instead of real geometry.

Right. So, background paintings, basically?

Let's see if Google can do this... ah, yes. Here we go...

http://www.lionking.org/~lynxcat/nimh/brisnico.jpg

How's *that* for a background? Of course, it doesn't move. Only the 
characters in front of it move. (Which are drawn in much lower detail.) 
There are scenes in the films where they have several layers of 
background which move in relation to each other which can create a 
parallex impression...

So basically what you're saying is the sky is wonderfully saturated 
because it was painted by a human being rather than computed by a 
hellish volumetric sampling algorithm? (Man, wouldn't it be cool to be 
able to paint like that?!!)


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From: Tim Nikias
Subject: Re: Saturation
Date: 23 Apr 2005 06:09:57
Message: <426a1ef5@news.povray.org>
> OK. Cos, one of the major problems I constantly have with POV-Ray is the
> image is too dark, or it's too light, or it looks washed out, or part of
> it is too bright but the rest is too dark, or......

What you might want to try is to use more saturated colors to begin with.
The less r and g you have in a blue color, the less it can get washed out
with standard white light sources. Additionally, using values above 1 for
dominant colors on an object can increase the amount of color you'll get for
less light. So even if a scene isn't lit with dominant lights, you'll get
dominant colors.

> So basically what you're saying is the sky is wonderfully saturated
> because it was painted by a human being rather than computed by a
> hellish volumetric sampling algorithm? (Man, wouldn't it be cool to be
> able to paint like that?!!)

Hell yeah, some of the matte paintings in Final Fantasy are so awesome, I
really wonder if it's worth the effort to create incredibly long renders for
a backdrop (not to mention that you can never be sure if everything comes
out alright unless you have done several dozens of long test-renders)... Too
bad POV-Ray doesn't come with a functionality to switch objects into layers.
Not because it needs it like other renderers which won't be able to handle
the entire scene at once (the Maya-Installations at our university come to
mind, where even a simple scene needed to be rendered in two layers, I was
astonished how little the inbuilt-renderer can handle), but because of
compositing and such. You could render the scene without a detailed
backdrop, but a rough one for radiosity, but later replace it with a better
one. Ah well, didn't mean to rant about POV-Ray, it's great as it is and you
can always find round-about ways to achieve what you want. :-)

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>


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From: Orchid XP v2
Subject: Re: Saturation
Date: 23 Apr 2005 10:27:54
Message: <426a5b6a@news.povray.org>
>>OK. Cos, one of the major problems I constantly have with POV-Ray is the
>>image is too dark, or it's too light, or it looks washed out, or part of
>>it is too bright but the rest is too dark, or......
> 
> 
> What you might want to try is to use more saturated colors to begin with.

Most of my scenes use things like rgb <1, 0, 0>. Can't get much more 
saturated than that... (I'm just not very imaginative with my colour 
choosing.)

> Additionally, using values above 1 for
> dominant colors on an object can increase the amount of color you'll get for
> less light. So even if a scene isn't lit with dominant lights, you'll get
> dominant colors.

Hmm... never ever tried doing that... (Although I do remember somebody 
tried using lights with negative RGB values to see what would happen.)


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From: Gilles Tran
Subject: Re: Saturation
Date: 23 Apr 2005 18:17:51
Message: <426ac98f@news.povray.org>

426a14c0$1@news.povray.org...

> OK. Cos, one of the major problems I constantly have with POV-Ray is the 
> image is too dark, or it's too light, or it looks washed out, or part of 
> it is too bright but the rest is too dark, or......

This problem is quite common in 3D. In fact even big movie productions can 
suffer from it (remember battle in Hulk, where all we could see were grayish 
shapes moving around the screen).

I still plan to write something for the wiki 
(http://www.wikipov.org/ow.asp?SceneLighting) but haven't got around to do 
it. My basic advice would go like this:
- be sure of your gamma settings
- make everything ambient 0. In particular, beware of the default ambient 
value in many textures provided with POV-Ray, particularly in textures.inc, 
metals.inc, woods.inc stones1.inc and stones2.inc. The non-zero ambient in 
these textures is pure legacy, but seems the main reason for having so many 
washed out pics.
- remember that real light is not clamped in the <0,1> range, and that 
neither is POV-Ray. Have a look at Jaime's lightsys macro and tinker with it 
to see the actual values output by the macro. This is often very surprising 
(VERY high intensity values, VERY short fade_distance).
- remember that real lights and real colours are rarely pure, like all white 
or all red. Search for digital images (or better, make your own) and sample 
them.
- use a tool like the Gimp or the color macros in colors.inc to play with 
the HSV colorspace (3.7.3.2 in the POV-Ray docs).
- use radiosity, starting with recursion_limit 1 instead of 2 or 3 (as in 
the scene template). Increase to 2 and higher only if necessary. Too high 
recursion values are the main reason why radiosity scenes are often washed 
out in POV-Ray (some people seem to think that the higher the better).
- and above all, learn about lighting schemes, like the classical 3-point 
lighting, and experiment with them http://www.3drender.com/light/3point.html

> Let's see if Google can do this... ah, yes. Here we go...
http://www.lionking.org/~lynxcat/nimh/brisnico.jpg
>

These links will give you a better idea of what matte paintings are in 
current moviemaking:
http://www.maxdennison.com/
http://www.dusso.com/

G.


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From: scott
Subject: Re: Saturation
Date: 5 May 2005 06:07:38
Message: <4279f06a$1@news.povray.org>
Orchid XP wrote:
> OK, take a quick look at this:
>
>
http://www.wallpaper.net.au/wallpaper/abstract/Abstract%20Car%20Alpha%20-%201024x768.jpg
>
> So, it's a reflective car. But how do they make it *look*
> reflective?? I mean, it doesn't take much to tell POV-Ray "please
> compute reflectiosn". But that, alone, doesn't make the thing *look*
> reflective. I've tried all sorts of things... but no matter what I
> scatter around the place to reflect off things, they just don't look
> very reflective. :-(

Two points here.

Firstly, you need to have an interesting and realistic environment for the
object to reflect.  In that example there are the clouds, a bright horizon,
and a bright sun.  For a quick cheat, try taking photos of your room (or
anywhere else) and using them as image_maps in the background.  I'm
experimenting with this at the moment and the results look pretty good.
I'll post to p.b.i if I get anything good.

Secondly, curves are best.  Flat objects don't reflect very interestingly.
Even cylinders don't reflect particularly well, because they only curve one
way.  You need to add rounds to your objects if they are geometrically
"square".  If you look at a square box, the edges will have highlights
because the edges are rounded, even if the rounds are tiny.  Complex curved
surfaces like cars always produce the "nicest" reflections, but they're
quite hard to model in POV unless you have an external editor for making the
patches.

> Also, take a look at
>
> http://www.pixar.com/featurefilms/abl/
>
> OK, so it's a picture of some cartoon characters. And not terribly
> interesting ones. But look at the image itself. It's sharp and crisp,
> but most of all, it looks lushously saturated. How do you *do* that? I
> can never seem to get the lighting right...

Make sure you set the light falloff to be 2 or higher.  Placing lights is a
very difficult thing to get right.  See where you are sitting now, think
about all the main light sources and how you can model them in POV.  For me,
I have a load of strip lights in the ceiling, but I think if I just placed 5
or 6 area lights that would do the trick.  Then I also have light coming in
from the window, so again I'd place an area light off to the side.

You can check the relative intensities and distances of the different light
sources by seeing where shadows fall and how dark they are.  Move your hand
around at different angles and heights above your desk and see how the
shadows look.  Then think what you'd need to do in POV to replicate that.
That should give you a pretty good start.

Copy the lighting in your room, model a few things around you roughly, stick
a reflective sphere in the middle, render with focal blur and I bet you it
will look pretty good.  Then you can start experiments with the textures :-)

> Similarly, check this out:
>
> http://www.finalfantasy-spiritwithin.com/www/image14.htm
>
> OK, those clouds would probably give POV-Ray a real headache, but how
> do they get the colours so good? Maybe I just suck at this...

I always find a good way is to use the color-picker tool to get RGB values
from photos, then use them in POV ;-)  If you're not using a sky_sphere, set
ambient 1 diffuse 0 then that will make sure that colouur is displayed.


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From: Mike Williams
Subject: Re: Saturation
Date: 5 May 2005 08:58:33
Message: <gGwLeBAGhheCFw3Z@econym.demon.co.uk>
Wasn't it scott who wrote:
>Orchid XP wrote:
>>
>> OK, those clouds would probably give POV-Ray a real headache, but how
>> do they get the colours so good? Maybe I just suck at this...
>
>I always find a good way is to use the color-picker tool to get RGB values
>from photos, then use them in POV ;-)

When I want to grab loads of colours from something like a cloudscape I
convert the image to a GIF, load it into IrfanView and export the
palette in PAL format.

In PAL format you get an ascii file with three lines of junk, then a
list of the RGB values of each palette entry. If you tweak the file by
inserting commas everywhere, you can #read the data with POV, divide by
255 and populate a colour_map.

-- 
Mike Williams
Gentleman of Leisure


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