le message de news:41c5c477@news.povray.org...
This is becoming very nice!!
Just a suggestion: usually, along the border of a wood, trees tend to be
smaller and have branches starting lower than inside the wood  because they
don't have to seek light.
Well another suggestion: two or three fences across that wide field
range....

regards

Marc

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Tim Nikias wrote:
> So, latest installment. After the macros for dropping snow onto objects were
> working, I tweaked a few hours (parsing times can get high at times, and
> small tweaks can have great impact, and thus, you quickly add up to long
> hours...) and went on with the image. A selection of four more trees were
> generated with Arbaro and are used with a randomization process to create
> the forest, which actually consists of roughly 3200 trees.
> 
> Some cleaning up of the sources is in order soon, as I've had to move quite
> some things around for several lightgroups. The main tree's trunk casts an
> arealight-shadow, but doesn't receive arealights itself, the foreground
> casts and receives arealights, the background only point-lights... I'm
> pondering what to place above (image-wise speaking, not in 3D) the cat. I've
> been experimenting with a small macro to create some random houses and
> create a little town, then again, I'd also find it fitting to somehow
> encircle the cat with a space of white, to further point out that it is
> alone and waiting for it's friend, the bird, to return (which is "back in
> spring", hence the small note on the tree).
> 
> The sky will of course get some clouds in due time.
> 
> Suggestions, comments and questions welcome,
> 
> regards,
> Tim

I'm floored every time you come out with a new image, time. Very 
impressed...and inspired too.

One comment, one suggestion and two questions. First the comment, the 
face on the cat looks a little strange. Maybe it doesn't at a higher 
resolution, I don't know. It's just a little difficult to tell where the 
facial features are. It almost looks like the cat's head is tilted to 
its left about 45 degrees, but then it also looks like it's pointing its 
nose at the sign and smiling. Is this just an illusion at the smaller 
size or am I right somehow? :)

Now for the questions. I was taking the garbage out this morning and had 
POV and snow on my mind (I promised myself I wasn't going to open up 
POV-Ray for about a month, but so far I've broken my promise twice and 
it's only half past nine.). I was trying to figure out what made the 
difference between real snow and raytraced snow - somehow the fake stuff 
always looked, well, fake...yours has excellent distribution, the right 
"blobbiness" - yes, it looks that way in real life, I checked - but it's 
missing that granulated powdery look. The snow at the base of the tree 
has it somewhat, but that's all.

I suppose this could be accomplished with a bump map or some averaged 
normals or something, but I was trying to think of a better way to do 
it. There seems to be a general sentiment running that bump-mapping is 
cheating somehow, and I don't like using normals to simulate actual 
shapes (personal preference, probably completely unfounded). So I 
wondered...would it be possible to use Surcoat to do the general snow 
layer with a good blob factor, then to do it again on top of that and 
shrink the blobs to a really tiny size so that they don't join at all, 
but rather look like little crystals sitting on top of the snow layer? 
Kind of like powdered sugar, in a way.

Second question: how does Surcoat handle the snow layers? Does it call 
them all blobs as a union or a merge or is it handled after the scene is 
created? I'm wondering whether it's possible to do extra 
texturing/finishing/interiors/normals on the snow particles without 
having to internally modify Surcoat.

Lastly, the suggestion...it seems likt there's a high "blue factor" in 
your snow. With such strong shadows I think it would be a tad more 
realistic if it were more blindingly white. Maybe it's that "artistic 
license" again...just a thought.

Overall incredible work. You're in my HOF book now. :)

~Mike

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Great ideas can take you farther than technical precision. You have both
there, so don't worry; it already is a great image and from now on it can
only get better.

I'm too much of a newbie to give you any advice. I think the image is great
as it is. Cheers.

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Tim Nikias wrote:
> Suggestions, comments and questions welcome,

   This looks fantastic! These macros should be of good use for a lot of 
things... About the image itself, I don't have enough experience with 
snow and cold places to comment on it (for example, is really the sky so 
violet there?).

--
Jaime

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> This is becoming very nice!!

Thanks!

> Just a suggestion: usually, along the border of a wood, trees tend to be
> smaller and have branches starting lower than inside the wood  because
they
> don't have to seek light.

I'm thinking about adding some smaller vegetation, like bushes, because
adding branches could be a little more difficult.

> Well another suggestion: two or three fences across that wide field
> range....

Yeah, I've been thinking about that possibility...

Regards,
Tim

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

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> Great ideas can take you farther than technical precision. You have both
> there, so don't worry; it already is a great image and from now on it can
> only get better.

Thank you very much for the kind words!

> I'm too much of a newbie to give you any advice. I think the image is
great
> as it is. Cheers.

Nah, don't underestimate your own taste! You're possibly right that you're a
newbie on the technical side of things, but you can still make suggestions
on what you think is missing or needs adjustment. :-)

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

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> One comment, one suggestion and two questions. First the comment, the
> face on the cat looks a little strange.

It is looking up at the sign. Modelling a face using blobs isn't that easy,
but on a higher res the viewing direction of the cat can be discerned more
easily. Since the cat *does* look like a cat, I wanted to improve on the
overall image before getting stuck with it...

> I suppose this could be accomplished with a bump map or some averaged
> normals or something, but I was trying to think of a better way to do
> it. There seems to be a general sentiment running that bump-mapping is
> cheating somehow, and I don't like using normals to simulate actual
> shapes (personal preference, probably completely unfounded). So I
> wondered...would it be possible to use Surcoat to do the general snow
> layer with a good blob factor, then to do it again on top of that and
> shrink the blobs to a really tiny size so that they don't join at all,
> but rather look like little crystals sitting on top of the snow layer?

Yes, that is possible. You'd just have to do a two-pass with Surcoat: one to
collect the initial, rough data, and then a second pass onto the blob. You'd
have to either render an orthographic view of the blob (to speed up the
sampling of the second pass) or just shoot samples at the entire boundary
box, but that shouldn't be a too big problem, right? ;-)

> Second question: how does Surcoat handle the snow layers?

Actually, all samples, along with their respective surface normal, are
simply saved into a file. A simple loop can then parse through the file and
while the File is defined, like this:

#fopen File Surcoat_Data read
#while (defined(File))
#read (File, Sample_Position, Sample_Normal)
//do some stuff
#end
#fclose File

I've prepared a simple set of macros for visualization, e.g. placing objects
at the samples' positions, or create a simple, spherical blob, or just place
spheres with a given radius. It should be easy to write your own
visualization macro, as the read-in (as seen above) is quite simple.

For the snow, I've written another set of macros which actually trace() the
surroundings of a sample to add some data like possible height, closest wall
and such, to generate heights for the snow. Instead of spheres, I use
cylinders in a blob to visualize the samples (along with the added data).
The processing of the original data into an extended set is of course more
scripting-biased, but that's the way it always is, right?

> Lastly, the suggestion...it seems likt there's a high "blue factor" in
> your snow. With such strong shadows I think it would be a tad more
> realistic if it were more blindingly white. Maybe it's that "artistic
> license" again...just a thought.

Hm, I'll think about that. Need to inspect some more winter photographs. :-)

> Overall incredible work. You're in my HOF book now. :)

Thanks for the praise. :-)

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

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>    This looks fantastic! These macros should be of good use for a lot of
> things...

Thank you! As for the macros: I hope so! Would rather have them see being
used than collecting dust on my website! :-) Release of them is still a
little off though, as I don't have the time to clean the code and write a
help at the moment.

> About the image itself, I don't have enough experience with
> snow and cold places to comment on it (for example, is really the sky so
> violet there?).

The sky is just a temporary placement, the colors will get adjusted to a
more realistic palette once I get to creating the clouds and such.

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

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"Tim Nikias" <JUSTTHELOWERCASE:timISNOTnikias(at)gmx.netWARE> wrote:
> The sky is just a temporary placement, the colors will get adjusted to a
> more realistic palette once I get to creating the clouds and such.

My suggestion would be to leave out the clouds and seriously consider
not altering the sky color either.  To me (a finn) it looks perfect,
although on one condition:  the date is, roughly, from March/April.

But it really is a very good looking image, and I congratulate you
on your execution of the snow dropping macros -- very convincing results.

--
jussi

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> My suggestion would be to leave out the clouds and seriously consider
> not altering the sky color either.  To me (a finn) it looks perfect,
> although on one condition:  the date is, roughly, from March/April.

March/April?! There's snow in the image, for god's sake! :-) Seriously
though, I want to take some pictures of the sky here (when it's cold and
clear with little haze, but some clouds) and use that as reference for
colors. As for the clouds, I don't want to overload the sky, just a few
details, as we here (not in Finnland ;-) don't have too many days with no
clouds. Thanks for the feedback though!

> But it really is a very good looking image, and I congratulate you
> on your execution of the snow dropping macros -- very convincing results.

Thank you! :-)

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

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