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17 Jul 2024 13:23:37 EDT (-0400)
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From: Ive
Subject: Re: Spectral Rendering with POV-Ray
Date: 21 Sep 2012 10:50:12
Message: <505c7ea4$1@news.povray.org>
Am 21.09.2012 13:23, schrieb Thomas de Groot:
> <sigh>
> Why is life so short?
> Why have days only 24 hours?
> Why is there real life?
> Why do I love POV-Ray so much?
>
While I understand that these questions are just rhetoric I still feel 
tempted to answer all of them. But as this goes completely OT just 
number three: Because otherwise - for the lack of recreation - humankind 
would be extinct within a few years.

;) -Ive


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From: nemesis
Subject: Re: Spectral Rendering with POV-Ray
Date: 21 Sep 2012 11:30:01
Message: <web.505c877b8647b6ff352a052d0@news.povray.org>
Ive <ive### [at] lilysoftorg> wrote:
> The animation feature of POV-Ray can be used to make it a spectral
> render engine. The basic idea is to render a set of gray-scale images
>   - each representing a specific wavelength - and finally combine them
> using the CIE color match function.
> To simplify this task I have created a few POV-Ray SDL scripts and some
> examples.
> You'll find the download link, some images and more explanation here:
>
> http://www.lilysoft.org/CGI/SR/Spectral%20Render.htm
>
> -Ive

amazing


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray
Date: 22 Sep 2012 03:13:25
Message: <505d6515@news.povray.org>
On 21-9-2012 16:49, Ive wrote:
> While I understand that these questions are just rhetoric I still feel
> tempted to answer all of them. But as this goes completely OT just
> number three: Because otherwise - for the lack of recreation - humankind
> would be extinct within a few years.

<grin> Absolutely right.

I think you did a great job. I shall do what you ask and try this out, 
and report back if I find something difficult to understand. I have some 
experience in writing tutorials and I know it is not really easy. It 
needs feedback to get better.

Thomas


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray
Date: 22 Sep 2012 03:55:55
Message: <505d6f0b$1@news.povray.org>
Ive, I am working on it and writing down a file with comments on your 
tutorial. I hope to be finished today, otherwise tomorrow.

Thomas


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray
Date: 22 Sep 2012 07:19:19
Message: <505d9eb7$1@news.povray.org>
Problem with Prism.pov:

unable to find: M_Spectral_Glass

Does not appear in any of the available files.

Thomas


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray
Date: 22 Sep 2012 07:23:55
Message: <505d9fcb$1@news.povray.org>
Before all else (I noted it in my comments):

In the command line, +E should be +FE
otherwise it does not save in exr format.

Thomas


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray: comments on the tutorial
Date: 22 Sep 2012 07:47:11
Message: <505da53f$1@news.povray.org>
Ive, I have the following suggestions for your online tutorial:

1) put the *Prerequisites* block at the top of the tutorial.

2) The command line option +E should be +FE (see Docs) in the tutorial 
and in all .pov files.

3) the *Quick Overview* block is a bit confusing as it mentions all kind 
of processes which are dealt with only later. I suggest to delete this 
block, or – better – to include it at the beginning of the *Some Hints* 
block.

4) In the *First Step* block, ColorChecker.pov does not render the shown 
image, strictly speaking. This is done by SpectralComposer.pov. I 
suggest to change the first paragraph to something like: “Render the 
file ColorChecker.pov animation. This will produce a series of 
grey-scale images of the GretagMacbeth(tm) ColorChecker Chart.”. Below, 
change the corresponding text: “...will create the final PNG image shown 
above. “

5) For better understanding just tell the user to uncomment #declare 
FName = "ColorChecker"; and to comment out #declare FName = 
"Diffraction"; That would be more comprehensive / less confusing.

Thomas


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From: Ive
Subject: Re: Spectral Rendering with POV-Ray: comments on the tutorial
Date: 22 Sep 2012 08:05:49
Message: <505da99d@news.povray.org>
Am 22.09.2012 13:47, schrieb Thomas de Groot:
> Ive, I have the following suggestions for your online tutorial:
>
> 1) put the *Prerequisites* block at the top of the tutorial.
>
> 2) The command line option +E should be +FE (see Docs) in the tutorial
> and in all .pov files.
>
> 3) the *Quick Overview* block is a bit confusing as it mentions all kind
> of processes which are dealt with only later. I suggest to delete this
> block, or – better – to include it at the beginning of the *Some Hints*
> block.
>
> 4) In the *First Step* block, ColorChecker.pov does not render the shown
> image, strictly speaking. This is done by SpectralComposer.pov. I
> suggest to change the first paragraph to something like: “Render the
> file ColorChecker.pov animation. This will produce a series of
> grey-scale images of the GretagMacbeth(tm) ColorChecker Chart.”. Below,
> change the corresponding text: “...will create the final PNG image shown
> above. “
>
> 5) For better understanding just tell the user to uncomment #declare
> FName = "ColorChecker"; and to comment out #declare FName =
> "Diffraction"; That would be more comprehensive / less confusing.
>

Thomas, thank you very much!
This is very helpful and I've corrected already all the "critical 
errors" within both the web.page and the zip-file:
+FE everywhere and M_Spectral_Glass from Prism.inc has changed to 
M_Spectral_Filter.
And I will also follow your advises but it might take some time because
literally I just hear RealLife(tm) urgent calling from outside...

... more later

- Ive


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From: Thomas de Groot
Subject: Re: Spectral Rendering with POV-Ray: comments on the tutorial
Date: 22 Sep 2012 10:16:53
Message: <505dc855$1@news.povray.org>
On 22-9-2012 14:04, Ive wrote:
> Thomas, thank you very much!
> This is very helpful and I've corrected already all the "critical
> errors" within both the web.page and the zip-file:
> +FE everywhere and M_Spectral_Glass from Prism.inc has changed to
> M_Spectral_Filter.
> And I will also follow your advises but it might take some time because
> literally I just hear RealLife(tm) urgent calling from outside...
>
> ... more later
>

You are welcome; glad to have been of help. If I find something else 
I'll tell you.

I am going to play some more with your macros. There are some 
interesting possibilities and the results are very nice.

Thomas


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From: Stephen
Subject: Re: Spectral Rendering with POV-Ray
Date: 22 Sep 2012 15:00:31
Message: <505e0acf$1@news.povray.org>
On 21/09/2012 3:40 PM, Ive wrote:

> Don't say that. I've spend a lot of time making its usage intuitive.
> Maybe I failed but I would welcome feedback on that matter to improve my
> didactic skills - I know that I suck in explaining things.
>

No, no. It is just my time is so limited nowadays. But a direct appeal 
for feedback cannot be ignored.


> Aaargh! You are so right! Why the heck does 2048 look so much more
> natural to me ;)
>

Because 2048 is 2^11, I would think.

>> I also like you music and that is saying something from someone who
>> thinks anything after the 18th Century is a bit too modern.


> You've mentioned this before and I still find it surprising. Especially
> since I do listen to almost all kinds of music of different styles and
> era but I'll have to admit that the 18th and 19th century is the deepest
> gap within my musical horizon. Well, I know all the "hits" all the
> symphonies and all the stuff everybody knowns but it fails to touch me.
> On the other hand, just recently I discovered Mozart's string quintets
> and I really do love them. Maybe a question of getting older?
>
>

I might be exaggerating a bit. I don’t like 20th Century “classical” 
music with maybe the exception of Benjamin Britain.
You should maybe give Mozart’s piano for 4 hands a listen. Bach and 
Handel transport me.


>> Bloody Hell! It sounds like a slow tempo Muppets theme. Tell me that I
>> am wrong. ;-)
>>
> Haven't heard the Muppets theme since over a decade but I guess you are
> not wrong ;)
> Actually the main theme of "Just Like A William Powell" is based on the
> typical "roaring 20ies" Charleston chord progression and I think the
> Muppets-theme uses the same chords.
> But the piano bridge between the verses of "...William Powell" cites a
> famous German tune from the 20ies (or 30ies, not sure) called "Ich
> brauche keine Millionen, mir fehlt kein Pfennig zum Glück" (rough
> translation: "Don't need millions, don't miss a penny for
> happiness/luck". Finally the instrumental part is bases on "Katz' Rag"
> (named after the composer) and this was one of the very first tunes I
> played on acoustic guitar when I was learning ragtime finger-picking
> style. To put it like John Renbourn (one of my favorite British
> guitarists): "I've always tried to play like Big Bill Broonzy - and I'm
> still trying!"
>

Thank you for that. I have just spent about an hour listening to Marika 
Rökk. I loved this clip on you tube:
http://www.youtube.com/watch?v=NOc8zFCzxno


> For short, as I have actually nothing to say and do not consider myself
> an artist I do with music the same as I do with my POV-Ray images: pack
> them full with tiny references and citations in an attempt to make them
> appear more interesting,

It works for me.

> but I guess it is not working that way,

I wouldn't say that.


> ....nonetheless I'll keep trying.
>

Good! Please do.
:-D

-- 
Regards
     Stephen


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