I started a wineglass project 3 years ago, but I got distracted after a
couple of weeks.  In mid-February, I resumed dabbling, and while nursing
a stomachache today, instead of vegging out on YouTube, I decided to
slap together a prototype.

This is an ISO standard wine tasting glass with 51 milliliters of some
kind of red wine.  I haven't programmed the meniscus yet.

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Cousin Ricky <ric### [at] yahoocom> wrote:
> I started a wineglass project 3 years ago, but I got distracted after a
> couple of weeks.  In mid-February, I resumed dabbling, and while nursing
> a stomachache today, instead of vegging out on YouTube, I decided to
> slap together a prototype.
>
> This is an ISO standard wine tasting glass with 51 milliliters of some
> kind of red wine.  I haven't programmed the meniscus yet.

Hi ! this looks very carefully done: the glass model has an very nice surface,
Two things that are probably due to WIP and not activating features during this
stage, are

a) From afar, the brightness seems sligthly off... as if the
texture-to-lighting-to-final-image gamma was somehow too high ...doubled? / not
reverse corrected as should happen in linear workflows allowing best contrast
preservation or maybe a media is at play in the room?

b) Then opening the image at maximum size... Doesn't the anti-aliasing look to
be off? or too low? Is it Method 3 and/or no AA value combined with a camera
aperture? Where this shows most is on edge of the glass where some kinds of
fireflies appear.

Are you using a branch, or vanilla 3.8 pov? I would be curious to know the
render time.

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Cousin Ricky <ric### [at] yahoocom> wrote:

> ... instead of vegging out on YouTube, I decided to

.... post a photograph on the POV-Ray forums.


Nice try, but you're not fooling anyone.

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On 2025-03-14 08:16 (-4), Mr wrote:
> 
> a) From afar, the brightness seems sligthly off... as if the
> texture-to-lighting-to-final-image gamma was somehow too high ...doubled? / not
> reverse corrected as should happen in linear workflows allowing best contrast
> preservation or maybe a media is at play in the room?

Probably just the overall lighting.  I did not use radiosity, and the
ambient may be a little high.

> b) Then opening the image at maximum size... Doesn't the anti-aliasing look to
> be off? or too low? Is it Method 3 and/or no AA value combined with a camera
> aperture? Where this shows most is on edge of the glass where some kinds of
> fireflies appear.

It's the hyper-white of the highlights.  Since POV-Ray 3.6, color values
are clipped post-anti-aliasing, which results in jaggies on bright
highlights.  The only way to solve this is post-processing.  Sam Benge
and I have both written tools in POV-Ray SDL that can do this, although
thus far only Sam has published his tool.

Prior to 3.6, colors were clipped before anti-aliasing, which made for
anemic-looking, albeit jaggies-free, highlights.  I actually prefer the
post-clipping of the newer POVs, because that can be fixed--especially
if the image is rendered to EXR.

> Are you using a branch, or vanilla 3.8 pov? I would be curious to know the
> render time.

Vanilla 3.7.0.10, actually.  3.8 would have given more accurate
highlights, but it wouldn't have changed the overall impression of the
scene.  I did not record the render time, but it must have been a
half-hour or so.

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On 2025-03-14 08:47 (-4), Bald Eagle wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
> 
>> ... instead of vegging out on YouTube, I decided to
> 
> .... post a photograph on the POV-Ray forums.
> 
> 
> Nice try, but you're not fooling anyone.

So then, I don't suppose you'll want to see my awsome render of a Rolex
watch?

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Cousin Ricky <ric### [at] yahoocom> wrote:
> I started a wineglass project 3 years ago, but I got distracted after a
> couple of weeks.  In mid-February, I resumed dabbling, and while nursing
> a stomachache today, instead of vegging out on YouTube, I decided to
> slap together a prototype.
>
> This is an ISO standard wine tasting glass with 51 milliliters of some
> kind of red wine.  I haven't programmed the meniscus yet.

I played around with adding a meniscus to drinking glasses before, but never got
anything I was really happy with.  I'd be interested in seeing what you come up
with.

I'd also like to see some "legs" on the wine after the swirl phase of tasting
it!

-- Chris R

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On 2025-03-14 13:59 (-4), Cousin Ricky wrote:
> On 2025-03-14 08:16 (-4), Mr wrote:
>>
>> a) From afar, the brightness seems sligthly off... as if the
>> texture-to-lighting-to-final-image gamma was somehow too high ...doubled? / not
>> reverse corrected as should happen in linear workflows allowing best contrast
>> preservation or maybe a media is at play in the room?
> 
> Probably just the overall lighting.  I did not use radiosity, and the
> ambient may be a little high.

Two more renders.  The first has a darker environment--brown walls,
although they don't show in the image.  Radiosity is still not used, but
my pre-fab environment computed a darker ambient because of the darker
walls.  The render time was 8 minutes for the photons and 33 minutes for
the render.

The second render is an outdoor patio scene using radiosity.

The glass design was tweaked for exactly 215 ml capacity, and the wine
level was tweaked to get exactly 50 ml.  Still no meniscus (yet).

>> b) Then opening the image at maximum size... Doesn't the anti-aliasing look to
>> be off? or too low? Is it Method 3 and/or no AA value combined with a camera
>> aperture? Where this shows most is on edge of the glass where some kinds of
>> fireflies appear.
> 
> It's the hyper-white of the highlights.  Since POV-Ray 3.6, color values
> are clipped post-anti-aliasing, which results in jaggies on bright
> highlights.  The only way to solve this is post-processing.  Sam Benge
> and I have both written tools in POV-Ray SDL that can do this, although
> thus far only Sam has published his tool.
> 
> Prior to 3.6, colors were clipped before anti-aliasing, which made for
> anemic-looking, albeit jaggies-free, highlights.  I actually prefer the
> post-clipping of the newer POVs, because that can be fixed--especially
> if the image is rendered to EXR.

Both renders were post-processed to add light bleeding.  The colored
fireflies on the rim and at the base of the stem are from the
high-dispersion crystal glass material.  I think the random appearance
results from complex multiple reflections that are too fine to bring out
the true detail at this resolution, and they are not bright enough for
my post-processing algorithm to smooth out.

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Attachments:
Download 'show_wine_preview.jpg' (49 KB) Download 'show_wine_preview-patio.jpg' (72 KB)

Preview of image 'show_wine_preview.jpg'

Preview of image 'show_wine_preview-patio.jpg'

Cousin Ricky <ric### [at] yahoocom> wrote:
> On 2025-03-14 13:59 (-4), Cousin Ricky wrote:
> > On 2025-03-14 08:16 (-4), Mr wrote:
> >>
> >> a) From afar, the brightness seems sligthly off... as if the
> >> texture-to-lighting-to-final-image gamma was somehow too high ...doubled? / not
> >> reverse corrected as should happen in linear workflows allowing best contrast
> >> preservation or maybe a media is at play in the room?
> >
> > Probably just the overall lighting.  I did not use radiosity, and the
> > ambient may be a little high.
>
> Two more renders.  The first has a darker environment--brown walls,
> although they don't show in the image.  Radiosity is still not used, but
> my pre-fab environment computed a darker ambient because of the darker
> walls.  The render time was 8 minutes for the photons and 33 minutes for
> the render.
>
> The second render is an outdoor patio scene using radiosity.
>
> The glass design was tweaked for exactly 215 ml capacity, and the wine
> level was tweaked to get exactly 50 ml.  Still no meniscus (yet).
>
> >> b) Then opening the image at maximum size... Doesn't the anti-aliasing look to
> >> be off? or too low? Is it Method 3 and/or no AA value combined with a camera
> >> aperture? Where this shows most is on edge of the glass where some kinds of
> >> fireflies appear.
> >
> > It's the hyper-white of the highlights.  Since POV-Ray 3.6, color values
> > are clipped post-anti-aliasing, which results in jaggies on bright
> > highlights.  The only way to solve this is post-processing.  Sam Benge
> > and I have both written tools in POV-Ray SDL that can do this, although
> > thus far only Sam has published his tool.
> >
> > Prior to 3.6, colors were clipped before anti-aliasing, which made for
> > anemic-looking, albeit jaggies-free, highlights.  I actually prefer the
> > post-clipping of the newer POVs, because that can be fixed--especially
> > if the image is rendered to EXR.
>
> Both renders were post-processed to add light bleeding.  The colored
> fireflies on the rim and at the base of the stem are from the
> high-dispersion crystal glass material.  I think the random appearance
> results from complex multiple reflections that are too fine to bring out
> the true detail at this resolution, and they are not bright enough for
> my post-processing algorithm to smooth out.

I think the contrast curve is much better now, especially on the glowy
reflection of glass and wine surface, A slight tweak could be to allow
absorption to restitute a little further penetrating light rays to have more of
a gradient in the red shadowed area, currently appearing too dark as if the wine
was almost opaque.

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