Hi all,

I bought a book about architecture the other week and it has a nice
picture on the front of the Guggemheim Museum in New York. I made a very
simple version of it in POV and started playing around with the
radiosity. What I haven't been able to achieve is that the walls stay
white, instead of the blue-ish tint they get now. And that the area
between the cones stays really dark. Any clue how I can achieve that? If
I turn up the ambient of the finish it gets whiter, but then the the
dark area goes a way as well.

And the walls are to clean as well they need something that gives it a
bit more structure, but normal bumps didn't look good on it. Any
suggestions are more then welcome.


Regards,

Thomas

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Thomas wrote:
> 
> Hi all,
> 
> I bought a book about architecture the other week and it has a nice
> picture on the front of the Guggemheim Museum in New York. I made a very
> simple version of it in POV and started playing around with the
> radiosity. What I haven't been able to achieve is that the walls stay
> white, instead of the blue-ish tint they get now.

Your sky is waaaay too blue.  It would only get this hue if it was -25
degrees outside.  Try bumping up the red and green components a bit, the
bluish tint will probably dissapear.  It looks like you tried to
compensate by cranking up the yellow in your concrete pigment, which
leads to the problem of having the recesses not dark enough.

> And that the area between the cones stays really dark.

You should also add grey buildings (just boxes should suffice)
off-camera to try to block some of the sky from lighting the building
from the sides.  It will help with the blue tint as well as make the
recesses darker.  [Note that I have never been to NY, so I don't know
what the surroundings look like, but I seem to recall seeing Will Smith
chasing an alien there, and it was smack in the middle of other
high-rise buildings]

Making your sky a gradient with a yellowish-white "sun" on one side
should also help with the shadows.

> And the walls are too clean as well they need something that gives it a
> bit more structure, but normal bumps didn't look good on it. Any
> suggestions are more then welcome.

You can fake it by adding a faint bozo pigment, using some crand or
rendering it to a bigger image and then reduce the size of the output in
your favorite image-manipulation program.

-- 
Francois Labreque | And a four year old carelessly banging on a toy
    flabreque     | piano is not only 'music', it's probably the last
        @         | moment of 'artistic purity' they'll ever enjoy
   videotron.ca   | before outside influences start corrupting their
                  | expression.    - Chris R.

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In article <3A9D3323.62E121D8@gmx.net>, Thomas <tho### [at] gmxnet> 
wrote:

> What I haven't been able to achieve is that the walls stay
> white, instead of the blue-ish tint they get now.

As Francois Labreque said, this is because your sky is too blue. Use a 
paler shade of blue, with more red and green, and maybe put some simple 
clouds on it. I usually use a big, hollow sphere with ambient 1 and a 
wrinkles pigment with a blue-white color_map for tests.


> And that the area between the cones stays really dark. Any clue how I 
> can achieve that? If I turn up the ambient of the finish it gets 
> whiter, but then the the dark area goes a way as well.

Turning up the ambient simply makes your objects themselves emit 
light...this is not what you want, unless you are doing luminescent 
panels covering everything. ;-)
Try increasing the recursions of the radiosity, and adjusting the 
"brightness" parameter.


> And the walls are to clean as well they need something that gives it a
> bit more structure, but normal bumps didn't look good on it.

Add "normal on" to the radiosity block to have it take normal modifiers 
into account in the radiosity calculations, this may be your problem.

Also, if you aren't doing so already, *use MegaPOV*. The radiosity in 
MegaPOV has been greatly improved over that in 3.1, and is much closer 
to what it is in 3.5. It is easier to use, faster, and has several 
bug-fixes. You can often just use the defaults or a generic set of 
settings and get good results.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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