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Am 10/18/2017 um 13:20 schrieb Paolo Gibellini:
>
> I remember the convincing procedural cat found in Cassidy.inc (Neil
> Alexander, 1998 - see http://www3.sympatico.ca/stoker/IGlvroom.html and
> http://objects.povworld.org/binaries/cat.inc) and the fun coolcat.inc in
> POV-RAy examples...
>
> But, seriously, the fur of a cat is very difficult to render and most of
> the previous examples I've seen was flat (e.g.
>
http://news.povray.org/povray.binaries.images/thread/%3C46fa10f0$1@news.povray.org%3E/
> and
>
http://news.povray.org/povray.binaries.images/thread/%3C553e9fd1%40news.povray.org%3E/),
> except for Nathan o'Brian cat
> (http://oz.irtc.org/ftp/pub/stills/1998-12-31/13kitty.jpg, used also
> here
>
(http://news.povray.org/povray.binaries.images/thread/%3Cweb.4f4a511d868e2771978383930@news.povray.org%3E/).
>
>
> Paolo
>
Hey, great, I wasn't aware of any of these. Fascinating that Nathan
O'Brian did experiment with fur-cats that long ago.
Thanks,
-Ive
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Am 10/17/2017 um 20:33 schrieb Bald Eagle:
> I'm always looking to learn how to increase the quality of my images, and reduce
> the amount of work it takes to create a scene (thereby freeing up more time to
> fine-tune it).
>
> Can you give us a bit of background on the creation of this scene?
>
Sure. But keep in mind that all I'm doing might very well not be the
best, easiest or simplest way.
> How long did it take you to model it?
15 years to evolve ;)
But seriously this is hard to say - every few years I did go back to
this scene and added, changed or improved on a few details.
The pitcher with the cap and handle is a good example. I do not remember
how long it took to create the original csg/lathe object, but as I
wanted to smash it, it had to be redone as a mesh. Modeling in Blender
was about half a hour but finding out how to break it and automatically
arrange the shards on the floor lasted a whole afternoon. There are
various ways, but I used the tool "Object:Cell Fracture" that ships with
blender but needs to be enabled within the user preferences window -
it's fun!
Or the lion-head-chairs: for the cat shots I did improve the fabric a
bit by using back-scattering (this was not available the last time I've
done anything with the scene) and making the fabric slightly translucent.
As meanwhile, to me, this scene is no longer about recreating the
original painting, more about doing silly things, I also changed my
original lion heads (friendly looking with a closed mouth) - close to
the ones in Vermeer's paintings - to some more wild looking animals with
open mouth where even the teeth can be seen.
Just for the cat shots of course, in the future I'll use the friendly
lions again ;)
> How many tools other than POV-Ray did you use?
In no particular order:
Lightroom - creating 16bps Adobe RGB texture maps from digital raw photos.
Photoshop - editing texture maps; creating bump, transparency and
specularity maps; also maps to drive the fur-mesh generation.
Wings3D - mesh modeling.
Blender - mesh modeling, breaking the pitcher.
Poser* - cloth room for creating the draping of the table rug.
Daz Studio - rigging and posing of the cat.
PoseRay - mesh conversion.
MS Visual Studio - to write simple tools to help scene development. The
fur-mesh could not have be done in SDL because it needs access to the
cat-mesh uv-coordinates for any given point at the surface.
*I don't use Poser anymore and would meanwhile do this with Blender.
>
> What sorts of simplifying "tricks" did you use (if any),
Err, well, I tend to make things more complicated than needed ;)
E.g. the pitcher, the pearls and the grapes are all slightly transparent
and use scattering media for a SSS effect.
I used this method before for some Chinese porcelain (before SSLT was
even introduced to POV-Ray) but while this worked great for the pearls,
for the grapes it should be just a little more intense and for the
pitcher, well, I'm pretty sure I would have gotten away without using it
there at all - and would have saved a few hours of render time for each
image where it is seen up close.
> and what interesting
> methods or algorithms did you employ (you already touched on the map for the
> hairs in the cat's fur)
>
While I was about to write "nothing special" there is one thing that is
worth mentioning (and I've almost forgotten after 15 years).
Here is the very first incarnation:
http://news.povray.org/povray.binaries.images/thread/%3C3d7e31fa%40news.povray.org%3E/
where I did not even try to recreate the painting but the old Cornell
University CGI copy of the painting that was the cover art of a book
that itself was considered 25 years ago the "bible of graphics
programming", I still have it ;)
To recreate the painting "The Music Lesson" for a raytracer, the
dimensions of the room are needed. Or, to be more precise, the
proportions (the dimensions in actual units, let's say cm, are less
important and can be established later by simply assuming the teacher
has the size of e.g. 170 cm).
Assuming that Vermeer did strictly follow the (since the Renaissance era
well established*) rules for perspective painting, I did a few
orthographic construction drawings (from the right and the top to
establish the view point, vanishing point, horizon line and such) and so
could determine at what angle the mirror above the virginals hangs from
the wall.
Within the mirror is also the edge visible where the rear wall meets the
floor - so the distance from the front to the rear wall can be
calculated. Now, the interesting thing is, assuming the window wall is
symmetrical, this matches exactly with the size for the window wall *if*
there is a third window and *if* all three windows have the same size
and *if* the wall size between the center window and the left/right
window is identical.
A lot of assumptions and ifs (and still no way to get the position for
the wall opposite the windows besides - by having the proportions so far
- assuming a room with nice overall proportions) - but I was quite
fascinated by these results so far.
At this time I was not aware of the book "Vermeer's Camera" by Philip
Steadman (maybe it wasn't even published), but later after having posted
an early version here in this newsgroup someone (sorry, don't remember
who it was) did mention it and I did immediately buy the book.
Philip Steadman did the same calculations I did and also did came to the
same conclusions regarding the dimensions of the room**. My image
"Vermeer's Room" (posted a few days ago) shows the result of my "reverse
engineering" process based on the painting.
And at my homepage are a few of my older renderings:
http://www.lilysoft.org/CGI/Music%20Lesson/musiclesson.htm
former home town) did publish a few books on this topic - himself being
mostly influenced by Italian painters.
**but I completely disagree with the arguments he makes for Vermeer's
usage of a camera obscura. These are all just cherry-picking or - in
other words - a good example for bad science.
> Any special comments on lighting?
>
Just GI, i.e. radiosity in POV-Ray terms. As a result, no material in
the scene uses specular or phong highlights but blurred reflections,
even the carpet (see below) - together with the ultra high radiosity
settings the main reason for the long render times.
And I do not post the radiosity settings on purpose, they are not
helpful because even with a powerful workstation every render took up to
45 hours and with a common high end i7 class machine it would take weeks.
> The carpet is beautiful - how did you texture and drape it?
>
My wife has some interest in old carpets (not only Persian) and created
over the years a huge collection of high resolution photographs.
As she (like me) shoots always in RAW format, these are perfect for
being used as image maps. I searched her collection for a rug that comes
close to the one seen in Vermeer's painting - regarding color tint and
ornamentation. Parts of the coloring are selective changed later in
Photoshop to get even closer.
Draping was done in the Poser cloth room, I think it was Poser 6 at the
time, I don't have Poser installed anymore.
The rug is also reflective using *very* blurred reflections and I'm sure
anisotropic, blurred reflections would make it even better but this is
one of the feature that I greatly miss when using POV-Ray as render engine.
>
> Thanks :)
>
You're welcome. And feel free to ask if you have any more questions. I
always wanted to add some scenes or at least some furniture objects to
my homepage for download, but - lazy as I am - never did it. Maybe some
day...
-Ive
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Am 10/17/2017 um 4:48 schrieb Dan Byers:
> Ive <ive### [at] lilysoft org> wrote:
>> Vermeer's cat...
>
> Wow, the whole series is very nicely done! I salute you :)
>
Thank you.
What happened to the stupid bee jokes - I'm a big fan and really miss
them ;)
-Ive
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Am 18.10.2017 um 13:20 schrieb Paolo Gibellini:
> I remember the convincing procedural cat found in Cassidy.inc (Neil
> Alexander, 1998 - see http://www3.sympatico.ca/stoker/IGlvroom.html and
> http://objects.povworld.org/binaries/cat.inc)
That's arguably impressive.
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On 18/10/2017 15:25, Ive wrote:
>
> What happened to the stupid bee jokes - I'm a big fan and really miss
> them ;)
Yeah, me too.
--
Regards
Stephen
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Ive <ive### [at] lilysoftorg> wrote:
> Sure. But keep in mind that all I'm doing might very well not be the
> best, easiest or simplest way.
No worries. These things have a life of their own. One needs to be practical.
"Never let the perfect be the enemy of the good"
> > How long did it take you to model it?
> 15 years to evolve ;)
Well, that explains a lot :D
> But seriously this is hard to say - every few years I did go back to
> this scene and added, changed or improved on a few details.
> The pitcher with the cap and handle is a good example.
.....
> There are
> various ways, but I used the tool "Object:Cell Fracture" that ships with
> blender but needs to be enabled within the user preferences window -
> it's fun!
Yes, it sounds that way, and adds an element which is very hard to achieve any
other way.
> > How many tools other than POV-Ray did you use?
> In no particular order:
>
> Lightroom - creating 16bps Adobe RGB texture maps from digital raw photos.
> Photoshop - editing texture maps; creating bump, transparency and
> specularity maps; also maps to drive the fur-mesh generation.
> Wings3D - mesh modeling.
> Blender - mesh modeling, breaking the pitcher.
> Poser* - cloth room for creating the draping of the table rug.
> Daz Studio - rigging and posing of the cat.
> PoseRay - mesh conversion.
> MS Visual Studio - to write simple tools to help scene development. The
> fur-mesh could not have be done in SDL because it needs access to the
> cat-mesh uv-coordinates for any given point at the surface.
That's quite the suite of graphics tools.
I need more free time to play with some of those...
> > What sorts of simplifying "tricks" did you use (if any),
>
> Err, well, I tend to make things more complicated than needed ;)
Yes, if you've seen any of the things I get involved with, I fully understand.
> Here is the very first incarnation:
>
>
http://news.povray.org/povray.binaries.images/thread/%3C3d7e31fa%40news.povray.org%3E/
That's pretty cool to see the origins of this. It's come a long way!
I'm glad you got to crank it through the Big Box and get a NICE render!
"I have simply used another Rembrandt for the moment."
Well, I suppose that's what anyone of us would have done in the same situation.
When you misplace something like that, it's best to just pop another out of the
cupboard...
:D
> To recreate the painting "The Music Lesson" for a raytracer,
.....
> Philip Steadman did the same calculations I did and also did came to the
> same conclusions regarding the dimensions of the room**. My image
> "Vermeer's Room" (posted a few days ago) shows the result of my "reverse
> engineering" process based on the painting.
> The rug is also reflective using *very* blurred reflections
I would have never guessed THAT! :O
- lazy as I am -
^^^^^^^^^^^^^^^^^^^^^^^
Yeah, totally slothful. <facepalm>
Thanks for giving some insight into the design and development of this scene.
Too often there are scenes that sort of seem to pop out of thin air, and we're
left to wonder: How the H would I ever do _that_!!!???
Thanks again for such a complete historical description!
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Stephen <mca### [at] aolcom> wrote:
> On 18/10/2017 15:25, Ive wrote:
> >
> > What happened to the stupid bee jokes - I'm a big fan and really miss
> > them ;)
>
>
> Yeah, me too.
>
> --
>
> Regards
> Stephen
People actually remember them?? That's a shock... haven't plunged down that
varmint hole in a looooong time. Probably will make a return visit, but other
things are holding my interest :)
That cat is just killing me...
--
Dan
roadkillpuppy.com
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On 20/10/2017 02:39, Dan Byers wrote:
> Stephen <mca### [at] aolcom> wrote:
>> On 18/10/2017 15:25, Ive wrote:
>>>
>>> What happened to the stupid bee jokes - I'm a big fan and really miss
>>> them ;)
>>
>>
>> Yeah, me too.
>>
>> --
>>
>> Regards
>> Stephen
>
> People actually remember them?? That's a shock... haven't plunged down that
> varmint hole in a looooong time. Probably will make a return visit, but other
> things are holding my interest :)
>
> That cat is just killing me...
>
Set the bees on it. ;-)
--
Regards
Stephen
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Stephen <mca### [at] aolcom> wrote:
> >
> > That cat is just killing me...
> >
>
> Set the bees on it. ;-)
>
> --
>
> Regards
> Stephen
Ooh... not sure if that's a fair fight ;)
--
Dan
roadkillpuppy.com
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On 22/10/2017 19:16, Dan Byers wrote:
> Stephen <mca### [at] aolcom> wrote:
>>>
>>> That cat is just killing me...
>>>
>>
>> Set the bees on it. ;-)
>>
>> --
>>
>> Regards
>> Stephen
>
> Ooh... not sure if that's a fair fight ;)
>
Of course not. I'm backing the bees. :-)
--
Regards
Stephen
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