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From: Thomas de Groot
Subject: Painted desert WIP [~260 kB]
Date: 2 Jul 2008 05:17:27
Message: <486b47a7@news.povray.org>
Suppose you decide to take a walk through on of your preferred deserts.

Suppose that mr. X, the famous action painter, decides that same day, to 
paint the desert from a balloon...

The image imposed itself while working with John VanSickle's height_field 
patchwork macro, in combination with some slope texture. Hidden in this 
landscape is an image from Sam Benge's Kingdom code used in a complex 
averaged pigment. The blocks are pixels in fact.

This is a wip. Still some radiosity issues (see shadowed angles of the 
blocks).

Thomas


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Attachments:
Download 'The Painted Desert_01.jpg' (254 KB)

Preview of image 'The Painted Desert_01.jpg'
The Painted Desert_01.jpg


 

From: Kyle
Subject: Re: Painted desert WIP [~260 kB]
Date: 2 Jul 2008 07:29:57
Message: <dipm64d2q3ns0e6e2e3i1kg5rgo3lf6etc@4ax.com>
Cool idea.  

In case you hadn't noticed, there's a lack of shadow behind the guy's heel too.


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From: Thomas de Groot
Subject: Re: Painted desert WIP [~260 kB]
Date: 2 Jul 2008 08:18:58
Message: <486b7232@news.povray.org>
"Kyle" <hob### [at] gatenet> schreef in bericht 
news:dipm64d2q3ns0e6e2e3i1kg5rgo3lf6etc@4ax.com...
> Cool idea.
>
> In case you hadn't noticed, there's a lack of shadow behind the guy's heel 
> too.

Yes, I had noticed. What worries me now is that even better radiosity 
settings and a black plane below the height_field do not change anything...

This reminds me of something...but what??

Thomas


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From: LightBeam
Subject: Re: Painted desert WIP [~260 kB]
Date: 2 Jul 2008 10:47:57
Message: <486b951d@news.povray.org>
Really nice, I luv it :-)


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From: Thomas de Groot
Subject: Re: Painted desert WIP [~260 kB]
Date: 3 Jul 2008 03:23:34
Message: <486c7e76$1@news.povray.org>
"LightBeam" <seb### [at] gmailcom> schreef in bericht 
news:486b951d@news.povray.org...
> Really nice, I luv it :-)

Merci  :-)

Thomas


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From: Cousin Ricky
Subject: Re: Painted desert WIP [~260 kB]
Date: 5 Jul 2008 01:40:01
Message: <web.486f07c34ab32a2c85de7b680@news.povray.org>
Kyle <hob### [at] gatenet> wrote:
>
> In case you hadn't noticed, there's a lack of shadow behind the guy's heel too.

I've had that problem when working on small scales, but not on a scale that i
feel should challenge POV's floating point accuracy.  As far as i can
determine, it's a bug.  I haven't brought it up in these newsgroups because i
haven't yet reproduced in in a simple scene.


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From: Thomas de Groot
Subject: Re: Painted desert WIP [~260 kB]
Date: 5 Jul 2008 03:29:02
Message: <486f22be@news.povray.org>
"Cousin Ricky" <ric### [at] yahoocom> schreef in bericht 
news:web.486f07c34ab32a2c85de7b680@news.povray.org...
> Kyle <hob### [at] gatenet> wrote:
>>
>> In case you hadn't noticed, there's a lack of shadow behind the guy's 
>> heel too.
>
> I've had that problem when working on small scales, but not on a scale 
> that i
> feel should challenge POV's floating point accuracy.  As far as i can
> determine, it's a bug.  I haven't brought it up in these newsgroups 
> because i
> haven't yet reproduced in in a simple scene.
>

That is interesting. The scale is reasonably scaled in the present scene. 
For instance, the figure is scaled to 0.2 from original, so nothing extreme 
here. However, I am not sure how the hf subdivision in John VanSickle's 
macro might influence the foreground scaling, although the final hf is 
scaled up.

Thomas


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From: Ive
Subject: Re: Painted desert WIP [~260 kB]
Date: 5 Jul 2008 08:29:30
Message: <486f692a$1@news.povray.org>
"Cousin Ricky" <ric### [at] yahoocom> wrote in message 
news:web.486f07c34ab32a2c85de7b680@news.povray.org...
> Kyle <hob### [at] gatenet> wrote:
>>
>> In case you hadn't noticed, there's a lack of shadow behind the guy's heel 
>> too.
>
> I've had that problem when working on small scales, but not on a scale that i
> feel should challenge POV's floating point accuracy.  As far as i can
> determine, it's a bug.

It's a feature! POV-Ray has to avoid self shadowing, actually I've meanwhile 
checked
the sourcecode to confirm my statements made in this thread:

http://news.povray.org/47fbebb1$1@news.povray.org

Maybe this "epsilon value " should be made adjustable by the user?


Thomas, I'm quite sure this is your problem, especially as you say you scaled 
your
poser figure by 0.2 and I usually scale them by a factor of 200.

-Ive


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From: Thomas de Groot
Subject: Re: Painted desert WIP [~260 kB]
Date: 5 Jul 2008 11:02:12
Message: <486f8cf4@news.povray.org>
"Ive" <lil### [at] hotmailcom> schreef in bericht 
news:486f692a$1@news.povray.org...

> It's a feature! POV-Ray has to avoid self shadowing, actually I've 
> meanwhile checked
> the sourcecode to confirm my statements made in this thread:
>
> http://news.povray.org/47fbebb1$1@news.povray.org
>
> Maybe this "epsilon value " should be made adjustable by the user?
>
>
> Thomas, I'm quite sure this is your problem, especially as you say you 
> scaled your
> poser figure by 0.2 and I usually scale them by a factor of 200.
>

Ive, thank you for reminding me of that thread!! I forgot about it. Maybe 
this will help also for the height_field? I shall experiment by upscaling 
the whole scene.

Thomas


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From: Cousin Ricky
Subject: Re: Painted desert WIP [~260 kB]
Date: 5 Jul 2008 22:20:00
Message: <web.48702a714ab32a2c85de7b680@news.povray.org>
"Ive" <lil### [at] hotmailcom> wrote:
> "Cousin Ricky" <ric### [at] yahoocom> wrote in message
> news:web.486f07c34ab32a2c85de7b680@news.povray.org...
> > Kyle <hob### [at] gatenet> wrote:
> >>
> >> In case you hadn't noticed, there's a lack of shadow behind the guy's heel
> >> too.
> >
> > I've had that problem when working on small scales, but not on a scale that i
> > feel should challenge POV's floating point accuracy.  As far as i can
> > determine, it's a bug.
>
> It's a feature! POV-Ray has to avoid self shadowing, [...]

That makes sense.  (Moves from "bug" to "feature" cubby hole.)

> Maybe this "epsilon value " should be made adjustable by the user?

I have an old book, _The Elements of Programming Style_, and it says not to use
absolute epsilons.  Never having written a ray tracing program myself (always
on my to-do list since i'd first heard the term, if not before), i don't feel
right telling the POV team what to do.  Not that i could demand my money back
or anything. ;-)


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