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!

I think the time has come to apply this to my Logo Planet scene. Stay tuned!

-- 
Thomas

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Op 17-1-2024 om 00:58 schreef Kenneth:
> To me, those parallel lines look similar to the typical behavior of an image_map
> applied to a 1X1X1-unit box-- where the edge pixels 'wrap around the sides' (as
> an analogy only.) I haven't examined the code examples here or run them yet--
> I'm currently testing other things-- but I wonder if a small scaling factor
> needs to be used *somewhere*, to try and eliminate that effect. Something like
> scale <0.9999,0.9999,1>. Sorry if this proposal seems simplistic, but it's the
> first thing that popped into my head.
> 
Thanks for thinking along, Kenneth!

> As for the textures etc not following the rotation of the whole object, that's a
> strange mystery...perhaps a hidden problem with the 'slope' pattern itself?

Yes, that is really strange, isn't it?

-- 
Thomas

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Op 17-1-2024 om 12:43 schreef Bald Eagle:
> 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.
> 

Ha! Next fascinating problem! Excellent! :-)

-- 
Thomas

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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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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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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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