Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 17-1-2024 om 04:40 schreef Samuel B.:
> > There will always be some stretching, since not all objects will be boxes or
> > superellipsoids aligned to one sole direction. You have to do your
> > transformations before applying the triplanar mapping.
> >
> Sam, I am very happy with this final development, thank you very much
> for your efforts!
>

No problem, Thomas. It was a fun exercise :)

I tried to tackle craters today, with mixed success. It's a surprisingly
difficult thing to model. Attached is an attempt to make a surface suitable for
close up shots. I went a bit overboard with the hills and small-scale noise, and
as a result the craters sort of got lost. (But that happens in real life as
well, if you've taken a close look at some of the Apollo moon landing photos.)

Sam

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Attachments:
Download 'crater-map-height-test2m_13s.jpg' (101 KB)

Preview of image 'crater-map-height-test2m_13s.jpg'

Op 19-1-2024 om 01:05 schreef Samuel B.:
> No problem, Thomas. It was a fun exercise :)
> 
> I tried to tackle craters today, with mixed success. It's a surprisingly
> difficult thing to model. Attached is an attempt to make a surface suitable for
> close up shots. I went a bit overboard with the hills and small-scale noise, and
> as a result the craters sort of got lost. (But that happens in real life as
> well, if you've taken a close look at some of the Apollo moon landing photos.)
> 
Maybe a little overdone at this scale but somehow I think the 
crater-feeling is there. Maybe going for larger structures first might help?

-- 
Thomas

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Le 2024-01-18 à 19:05, Samuel B. a écrit :
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Op 17-1-2024 om 04:40 schreef Samuel B.:
>>> There will always be some stretching, since not all objects will be boxes or
>>> superellipsoids aligned to one sole direction. You have to do your
>>> transformations before applying the triplanar mapping.
>>>
>> Sam, I am very happy with this final development, thank you very much
>> for your efforts!
>>
> 
> No problem, Thomas. It was a fun exercise :)
> 
> I tried to tackle craters today, with mixed success. It's a surprisingly
> difficult thing to model. Attached is an attempt to make a surface suitable for
> close up shots. I went a bit overboard with the hills and small-scale noise, and
> as a result the craters sort of got lost. (But that happens in real life as
> well, if you've taken a close look at some of the Apollo moon landing photos.)
> 
> Sam
That's pretty good.

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> Nice work - that's looking really good!  :)
>
> So now here's a question - while trying to hunt down an answer to WFP's default
> importance question, I stumbled upon a thread where clipka discusses
> pleochromism.
>
> https://en.wikipedia.org/wiki/Pleochroism
>
> I know that I've brought up the topic of wet paper in the past in this regard.
>
> It seems that this approach might also make for a good anisotropic effect if we
> roll some layered texturing + filter/transmit into it?
>
> What do you think?
>
> - BW
>
> (You wouldn't believe how hard it is to find an example image of this effect)

For photographic examples, maybe look up tourmaline and axinite/ferroaxinite.

It's an interesting problem. I think rendering pleochromism accurately would
require access to POV-Ray's shader system at a level not exposed to the end user
(i.e., the source code would have to be altered). But maybe you could do as you
seem to suggest, and try using a slope pattern to drive two textures with
differently filtered pigments.

This and other types of special optical effects (such as chatoyancy) are things
most renderers have trouble with. I expect to see such effects supported by
future renderers as time goes on.

Sam

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Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 19-1-2024 om 01:05 schreef Samuel B.:
> > I tried to tackle craters today, with mixed success. [...]
> >
> Maybe a little overdone at this scale but somehow I think the
> crater-feeling is there. Maybe going for larger structures first might help?
>
> --
> Thomas

There's a sweet spot I want to hit, something around the scale one might see
depicted in a moon landing photo.

I managed to get the scale closer to what I want (see attached image), but it's
still a bit too close up.

Sam

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Attachments:
Download 'crater-map-height-test0m_37s.jpg' (168 KB)

Preview of image 'crater-map-height-test0m_37s.jpg'

Alain Martel <kua### [at] videotronca> wrote:

> > [...] craters today [...]
>
> That's pretty good.

Thanks Alain.

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Op 22/01/2024 om 02:27 schreef Samuel B.:

> There's a sweet spot I want to hit, something around the scale one might see
> depicted in a moon landing photo.
> 
> I managed to get the scale closer to what I want (see attached image), but it's
> still a bit too close up.
> 
Well, this is almost reaching a Wow-effect :-) Very well done indeed, 
Sam! I am impressed with the casual (?) way in which you seem to 
generate such things...

-- 
Thomas

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"Samuel B." <stb### [at] hotmailcom> wrote:
>
> There's a sweet spot I want to hit, something around the scale one might see
> depicted in a moon landing photo.
>
> I managed to get the scale closer to what I want (see attached image), but it's
> still a bit too close up.
>
Both of your images look really great, like the surface of asteroids--from the
photos that have been returned from spacecraft that have actually made landings.
Your result looks like an accumulation of loosely-held debris that has been
pulverized by micro-meteoroids over eons of time. Nice!

I still have a soft spot for those quaint old sci-fi movie depictions of
sharp-edged craggy mountains and craters on outer-space planets...but alas, that
appearance has been proven false.

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Op 23/01/2024 om 16:48 schreef Kenneth:
> "Samuel B." <stb### [at] hotmailcom> wrote:
>>
>> There's a sweet spot I want to hit, something around the scale one might see
>> depicted in a moon landing photo.
>>
>> I managed to get the scale closer to what I want (see attached image), but it's
>> still a bit too close up.
>>
> Both of your images look really great, like the surface of asteroids--from the
> photos that have been returned from spacecraft that have actually made landings.
> Your result looks like an accumulation of loosely-held debris that has been
> pulverized by micro-meteoroids over eons of time. Nice!
> 
Yes, that was also my impression indeed.

> I still have a soft spot for those quaint old sci-fi movie depictions of
> sharp-edged craggy mountains and craters on outer-space planets...but alas, that
> appearance has been proven false.
> 
Space is infinite, so maybe.... ;-)

-- 
Thomas

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Il 17/01/2024 04:40, Samuel B. ha scritto:
> "Samuel B." <stb### [at] hotmailcom> wrote:
>> it would appear that if you wish to rotate your objects you have to put up with
> 
> some issues.
> 
> There will always be some stretching, since not all objects will be boxes or
> superellipsoids aligned to one sole direction. You have to do your
> transformations before applying the triplanar mapping.
> 

A beautiful effect, Sam!
This image is a candidate for my next wallpaper.

Paolo

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