"Chris R" <car### [at] comcastnet> wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
> > On 2021-12-15 5:10 PM (-4), Chris R wrote:
> > >
> > > Looking at the picture in detail, I was unhappy with the way the puddle melting
> > > off of the snowman looked.  ...
> >
> > I didn't comment on the snowman before, because I didn't know if you
> > wanted it to be real snow. But now that I see that it's melting, I have
> > a couple of suggestions.
> >
> > First off, the diffuse value needs to be higher, close to 1.0.  And if
> > you are *not* using radiosity, the ambient value needs to be scaled up
> > proportionately.
> >
> > Second, snow really needs SSLT.  Of course, this will slow down the
> > render even more.  If you prefer to finish rendering by February, you
> > can cheat by adding a bit of emission to the snow in lieu of SSLT; I
> > once abused the ambient keyword this way to get a subsurface effect on
> > some beach balls.  If you cheat in this manner, then you may have to
> > take the diffuse below 1.0 to compensate for the "glow."
> >
> > Otherwise, the scene looks great!
>
> Thanks for the suggestions.  I keep waffling on whether to make the snow more
> realistic or not.  The scene is a bunch of ornaments, so the melting snowman is
> meant to be a bit of humor, but I had also considered making him a real snowman
> who just happens to have wandered into the scene.  I'll try some of your
> suggestions as I can see other uses for having a good model for snow.
>
> -- Chris R

I started playing around with subsurface in the finish for the snowballs.  After
fiddling with settings I could get some very convincing looking ice-balls, but
I'm not sure how to get it to look more like snow.

A few other things I noticed in my experiments:
 - Using subsurface dampens the effects of any normals in the texture pretty
dramatically.  This isn't too much of an issue since my snowballs are
isosurfaces and I can just translate the normals into perturbations on the
sphere shape.  I assume that's a known effect due to the subsurface algorithm,
it just surprised me.
 - There is an interaction between the diffuse setting in the finish and
subsurface.  I found if diffuse is too high, I get a very weird, reflective
surface.  I wonder if this is related to the caveats in the wiki about
zero-values in colors used for subsurface, or if it's some undocumented
interaction.

-- Chris R

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On 16/12/2021 10:12 pm, Chris R wrote:
> "m@b" <sai### [at] googlemailcom> wrote:
>> On 16/12/2021 5:10 am, Chris R wrote:
>>> "Chris R" <car### [at] comcastnet> wrote:
>>>> A bit of a work-in-progress, but far enough along to show.  This took about
>>>> 4-days to render without any camera blur, which I'd like to add at some point.
>>>>
>>>> There are a few more ornaments/elements I'd like to add in for interest.  I'll
>>>> probably have to play with the lights a bit or it will never finish rendering
>>>> before the holidays are over... :-;
>>>>
>>>> -- Chris Rath
>>>
>>> Looking at the picture in detail, I was unhappy with the way the puddle melting
>>> off of the snowman looked.  So, in true geek fashion, I looked up the theory
>>> behind surface tension of water when puddling on a solid surface, and rewrote
>>> the macro that generates the puddle to take all of that into account.
>>>
>>> Here is a closeup test view of the snowman with the new puddle, with which I am
>>> quite happy now.  I will probably have to update the scene to make the puddle
>>> more obvious in the full scene, because it's kind of hard to notice now.
>>>
>>> Of course, now I'm unhappy with the scarf, so I'll be working on that next...
>>>
>>> -- Chris Rath
>>
>> Here is my take on a melting snowman:
>> <https://youtu.be/puo_eVkz0gY>
>>
>> (Work in progress)
>> (In TikTok format)
>>
>> m@
> 
> Nice!  I thought about doing an animation of my snowman melting, and having the
> puddle grow as he does so.  However, it all renders so slowly that I'd have to
> rent a big server farm to get all of the frames done in my lifetime...
> 
> Any particular tools you use to convert frames to movies?
> 
> -- Chris Rath
> 
> 

<https://ffmpeg.org/>   is very versatile, you can call it as a shellout 
from POV-Ray.

m@

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"Chris R" <car### [at] comcastnet> wrote:
> "Chris R" <car### [at] comcastnet> wrote:
> > A bit of a work-in-progress, but far enough along to show.  This took about
> > 4-days to render without any camera blur, which I'd like to add at some point.
> >
> > There are a few more ornaments/elements I'd like to add in for interest.  I'll
> > probably have to play with the lights a bit or it will never finish rendering
> > before the holidays are over... :-;
> >
> > -- Chris Rath
>
> Looking at the picture in detail, I was unhappy with the way the puddle melting
> off of the snowman looked.  So, in true geek fashion, I looked up the theory
> behind surface tension of water when puddling on a solid surface, and rewrote
> the macro that generates the puddle to take all of that into account.
>
> Here is a closeup test view of the snowman with the new puddle, with which I am
> quite happy now.  I will probably have to update the scene to make the puddle
> more obvious in the full scene, because it's kind of hard to notice now.
>
> Of course, now I'm unhappy with the scarf, so I'll be working on that next...
>
> -- Chris Rath

Here's an updated version of the snowman using subsurface in the finish.  I
moved the normals into the isosurface itself, and changed the scale to make the
bumpy snow smaller, and then used a subsurface with a translucency of 0.1 and a
diffuse of 0.7.  It still looks like an ornament, but is fluffier, rather than
ceramic-looking.

I am rendering another version with a translucency of 0.5 that looks more like
real snow.  I'll post it when it finishes.

-- Chris R

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Preview of image 'snowmen_sslt2.png'

"Chris R" <car### [at] comcastnet> wrote:
> "Chris R" <car### [at] comcastnet> wrote:
> > "Chris R" <car### [at] comcastnet> wrote:
> > > A bit of a work-in-progress, but far enough along to show.  This took about
> > > 4-days to render without any camera blur, which I'd like to add at some point.
> > >
> > > There are a few more ornaments/elements I'd like to add in for interest.  I'll
> > > probably have to play with the lights a bit or it will never finish rendering
> > > before the holidays are over... :-;
> > >
> > > -- Chris Rath
> >
> > Looking at the picture in detail, I was unhappy with the way the puddle melting
> > off of the snowman looked.  So, in true geek fashion, I looked up the theory
> > behind surface tension of water when puddling on a solid surface, and rewrote
> > the macro that generates the puddle to take all of that into account.
> >
> > Here is a closeup test view of the snowman with the new puddle, with which I am
> > quite happy now.  I will probably have to update the scene to make the puddle
> > more obvious in the full scene, because it's kind of hard to notice now.
> >
> > Of course, now I'm unhappy with the scarf, so I'll be working on that next...
> >
> > -- Chris Rath
>
> Here's an updated version of the snowman using subsurface in the finish.  I
> moved the normals into the isosurface itself, and changed the scale to make the
> bumpy snow smaller, and then used a subsurface with a translucency of 0.1 and a
> diffuse of 0.7.  It still looks like an ornament, but is fluffier, rather than
> ceramic-looking.
>
> I am rendering another version with a translucency of 0.5 that looks more like
> real snow.  I'll post it when it finishes.
>
> -- Chris R

And here's the snowier one...

-- Chris R

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Op 18/12/2021 om 05:03 schreef Chris R:
> 
> And here's the snowier one...
> 
I think I prefer this one. To better show the translucency, put the 
light behind the snowman.

-- 
Thomas

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"Chris R" <car### [at] comcastnet> wrote:
> A bit of a work-in-progress, but far enough along to show.  This took about
> 4-days to render without any camera blur, which I'd like to add at some point.
>
> There are a few more ornaments/elements I'd like to add in for interest.  I'll
> probably have to play with the lights a bit or it will never finish rendering
> before the holidays are over... :-;
>
> -- Chris Rath

Hi Chris,

Nice and warm scene. I like the textures of the presents packaging, and the star
ornaments remember me of the ones I had fun to make every year as a child
(nostalgic mood triggered). The chains (?) holding them are barely visible, they
would surely benefit of being thicker. The last version of the snowman you
posted looks good, but aren't the dark spot a bit too dark ? The new puddle
looks good too. In the original scene it's quite hidden behind the lights. A
different composition there may help ? Also I thought the texture of the table
could be improved. To be honest I don't quite understand what kind of material
it is.

Merry Christmas to you too and to all the POV-Ray community !

Pascal

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"Chris R" <car### [at] comcastnet> wrote:
> And here's the snowier one...


Yeah that's looking good! I would suggest making the dark parts a little less
dark, but it also looks great as it currently is.

Kind regards,
Dave Blandston

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"BayashiPascal" <bai### [at] gmailcom> wrote:
> "Chris R" <car### [at] comcastnet> wrote:
> > A bit of a work-in-progress, but far enough along to show.  This took about
> > 4-days to render without any camera blur, which I'd like to add at some point.
> >
> > There are a few more ornaments/elements I'd like to add in for interest.  I'll
> > probably have to play with the lights a bit or it will never finish rendering
> > before the holidays are over... :-;
> >
> > -- Chris Rath
>
> Hi Chris,
>
> Nice and warm scene. I like the textures of the presents packaging, and the star
> ornaments remember me of the ones I had fun to make every year as a child
> (nostalgic mood triggered). The chains (?) holding them are barely visible, they
> would surely benefit of being thicker. The last version of the snowman you
> posted looks good, but aren't the dark spot a bit too dark ? The new puddle
> looks good too. In the original scene it's quite hidden behind the lights. A
> different composition there may help ? Also I thought the texture of the table
> could be improved. To be honest I don't quite understand what kind of material
> it is.
>
> Merry Christmas to you too and to all the POV-Ray community !
>
> Pascal

Thanks for the comments.  I was playing around with some new rough-wood shapes
and textures based on the isowood3 macros, and was using the pigments from that
set of include files as well.  I have some older macros that I think give better
results; I may revert to those and see if the table gets more convincing.

Merry Christmas

-- Chris R

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Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 18/12/2021 om 05:03 schreef Chris R:
> >
> > And here's the snowier one...
> >
> I think I prefer this one. To better show the translucency, put the
> light behind the snowman.
>
> --
> Thomas

The snowman is taking on a life of his own.  Still need to do some work on the
scarf.  I added more texture to his arms, and the nose needs more texture as
well.  I'll have to see about more prominent placement that makes the puddle
more visible in the full scene, and see how much the sslt affects the total
rendering time...

(BTW: This was just a moderate setting for radiosity as well, and the light is
only a point light since this is just my testing scene.)

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Preview of image 'snowmen_sslt6.png'

Op 20/12/2021 om 21:52 schreef Chris R:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Op 18/12/2021 om 05:03 schreef Chris R:
>>>
>>> And here's the snowier one...
>>>
>> I think I prefer this one. To better show the translucency, put the
>> light behind the snowman.
>>
>> --
>> Thomas
> 
> The snowman is taking on a life of his own.  Still need to do some work on the
> scarf.  I added more texture to his arms, and the nose needs more texture as
> well.  I'll have to see about more prominent placement that makes the puddle
> more visible in the full scene, and see how much the sslt affects the total
> rendering time...
> 
> (BTW: This was just a moderate setting for radiosity as well, and the light is
> only a point light since this is just my testing scene.)

This looks very convincing to me.

[nitpicking] Maybe the snow seems a bit polluted by industrial fall out 
from its original surroundings? [/nitpicking]  :-)

-- 
Thomas

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