Op 21-4-2021 om 12:51 schreef Bald Eagle:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> I realise that I have taken
>> on a major investigation :-) and that is ok.
> 
> So did I while writing this!
> 
> 
>> Imo, the white represents the quartz veins that cut through the
>> granites. In the original code they came out as mere "clouds" of grey; I
>> brought them back at least as something looking like veins (the top
>> texture). See the examples I provided.
> 
> IIRC, the marble pattern is just a series of repeating lines that attains a
> marble look due to the turbulence.   Maybe make a material_map using turbulated
> marble and have the granite and quartz materials be the entries.
> 
Turbulence is the keyword assuredly. In the latest version (in examples 
shown above) the quartz veins are partly controlled by warp {turbulence 
...}. Which reminds me: warp {} is another one of those things 
"learned". The use of marble (or agate maybe?) may be useful; 
investigation required.

[Tonight, I am going to browse my old textbooks to get some more useful 
info about granites. Feels like old times; I didn't specialise in hard 
rock geology but rather in sedimentary environments. However, those 
stony things were part of the curriculum and, I think I mentioned it, 
the penultimate ice age conveniently brought Scandinavian granites to 
this region, and I have some of them in my backyard. I wouldn't be 
surprised if they were also related to the North American granites of 
the east coast of US and Canada through the action of plate tectonics. 
But that is a completely different story.]

-- 
Thomas

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hi,

"Bald Eagle" <cre### [at] netscapenet> wrote:
> "jr" <cre### [at] gmailcom> wrote:
>
> > but how will a numpty like self know how to select?
>
> You won't.  It will be one those fun mystery things, like a grab-bag, an egg
> hunt, voting.  Or dating.

fun, huh?


> Actually, part of the idea I had, which is somewhat demonstrated in the stuff I
> posted for TdG, is that, while not self-documenting, the code can be made to be
> "self-documentable" - in that, the verbose feature embedded into all of the
> macros could be turned on by such an array instantiation macro, and then you'd
> generate a list of entries upon execution.  Really, the idea was to have them
> available for random selection...

for supplementary info perhaps.  but before the parser can spit out info, I
already need to have a scene, no?  so, I would need (some) information up front.


> > I do hope that there will a
> > few introductory paragraphs discussing, and a small table laying out, the
> > principal (POV-Ray) components making "granite"; their role and useful parameter
> > ranges, etc.
>
> Could do that, or issue a #warning depending on values of macro parameters.
> Might just imply correct values by using min/max in macro definition, or
> comments.
>
> I agree, but I can see the line between "include file" and "geology textbook"
> becoming rapidly blurred.

maybe you misread, maybe I put it poorly.  "geology textbook" -- I'm sure that
some "background" info for each variant would be nice to have, to help
contextualise.  what I tried to say is I'd like to read "why we fake granite in
POV the way we do, how do we work around the limitations of the tools in the
box, this POV-Ray feature is used because ..." etc.

note to Thomas: _please_ correct the spelling to 'mahogany'.


regards, jr.

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Op 21-4-2021 om 13:56 schreef jr:
> note to Thomas: _please_ correct the spelling to 'mahogany'.

I have been wondering about the spelling. After (again) assessing the 
occurrence of both spellings on the net, it seems indeed that "Mahogany" 
is the correct one.

I followed Daniel Mecklenburg's original (wrong) spelling from the start.

Additional Names: Dakota Mahagony,Dakota Mahogany,Mahogany 
Dakota,Mahogany Dakota America,Rushmore Mahogany,Select Mahogany,Sunset 
Mahogany,Brown Velvet Mahogany,Whetstone Mahogany,American 
Bouquet,Carnelian Granite    :-)

see: https://www.stonecontact.com/dakota-red-granite/s618

I shall correct but I wonder if I am not going to name it: "Dakota Red 
Granite" instead.

-- 
Thomas

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in news:web.608012f064981f5c79819d986cde94f1@news.povray.org jr wrote:

> "fake granite

've been looking at this thread with half an eye only. I worked in the 
graphics industry for quite a while and one of my jobs was pattern 
designer & colorist. The one thing I learnt,

People want what they think looks like the real thing. Not what the real 
thing actually looks like.

I have a colorised concrete floor in my house. The top layer has been 
ground off into the "grain". "What a nice marble floor" ... it looks more 
like a coarse granite ... it is closest to man made terazzo .... But still 
"a nice marble floor" ;)

https://ingoogni.nl/stuff/IMG_2021_04_21_0277_s.jpg with a nice line of 
light.

Ingo

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hi,

Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 21-4-2021 om 13:56 schreef jr:
> > note to Thomas: _please_ correct the spelling to 'mahogany'.
>
> I have been wondering about the spelling. After (again) assessing the
> occurrence of both spellings on the net, it seems indeed that "Mahogany"
> is the correct one.

perhaps also to do with accessing the net from the Netherlands vs the UK?  both
Google and Wiktionary don't think much -- anything! -- of 'mohogany'.


> I followed Daniel Mecklenburg's original (wrong) spelling from the start.
>
> Additional Names: Dakota Mahagony,Dakota Mahogany,Mahogany
> Dakota,Mahogany Dakota America,Rushmore Mahogany,Select Mahogany,Sunset
> Mahogany,Brown Velvet Mahogany,Whetstone Mahogany,American
> Bouquet,Carnelian Granite    :-)
>
> see: {...}
>
> I shall correct but I wonder if I am not going to name it: "Dakota Red
> Granite" instead.

do "mahogany granites" occur in places other than the Dakotas? if yes, I'd put
the "Dakota Red" plus latin nomenclature with the by-variant "background" info.

(and thanks for making change to spelling)


regards, jr.

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Thomas de Groot <tho### [at] degrootorg> wrote:
> I think we are on the verge of version 2.0 of granites21.inc. Thanks to
> your comments important improvements have been made or are pending. So,
> thank you indeed for your comprehensive contributions.
>
> Attached are examples of the latest developments. All the textures have
> been wrapped into material{} with an ior of quartz (1.6) and now include
> a finish with fresnel. The tentative to use the albedo keyword however,
> has been abandoned for the time being as too difficult apparently to use
> in any way. Without being exclusive, thanks to Alain and Maurice, and of
> course the usual suspects Bald Eagle and Kenneth.
>
> In a next stage, the use of more elaborate macros are planned, including
> sslt possibilities for instance. Bald Eagle has proposed a first version
> of such a macro and I am going to study it and see how to integrate
> things. In the same way, Jr proposed a HowTo html file where for
> instance the content of the headers and additional info can be provided.
> Thanks to both of you.
>
> More discussions can and will follow here of course, but a new version
> of the package will be uploaded in a new post in due time.
>
> --
> Thomas

Getting closer indeed! Now it has much more scale variations. Credit
(unwillingly :-P) deserved by Ive for showing us merits of the original files.
It might appear one could still prefer Ive's restored original version for the
single occurrences showed. At least its contrast curve could stay the reference.

But as you geologist said, its bigger scale is misleading. For having struggled
to do something that stays consistent at various scales, I know that you're
tackling something more demanding but keep hope, do not give up, try to reach an
as pleasing color curve. Theoretically, it could even get better than the
original as the new pov version can produce more nuances. I believe at this
stage showing both the current one and a much closer up framed render would do
it justice.

*Saturation of the colors should be slighly more and brightness slightly less,
but don't look at the picture straight out of the renderer, only after applying
it the gamma above 1.8 and below 2.5. if your rendered frame display gamma
doesn't do that. I would try playing either in very small amounts with the
brilliance keyword. or switch to another shading model if they did get
implemented since Uberpov? if they haven't the #brilliance shift kind of does
that "shading model translation" (OrenNayar Blinn would have sigmas for various
rocks well referenced I think).

*The specularity looks somewhat wrong sorry to be that vague: did you use
specular or phong, because what I more clearly meant was that it looks like
phong : too blurry.


Now it's just all bonus, though, the material feels really official includable
level already!

Thanks for your work !

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ingo <ing### [at] tagpovrayorg> wrote:
> in news:web.608012f064981f5c79819d986cde94f1@news.povray.org jr wrote:
>
> > "fake granite
> ...
> People want what they think looks like the real thing. Not what the real
> thing actually looks like.

so true.

for (Heinrich) Heine it was Germany (in English, though it "get's lost in
translation"[*]): if I think of Germany at night, I'm robbed of my sleep.  for
me, it's people.  :-)

[*] "Denk ich an Deutschland in der Nacht,
     dann bin ich um den Schlaf gebracht".

> I have a colorised concrete floor in my house. The top layer has been
> ground off into the "grain". "What a nice marble floor" ... it looks more
> like a coarse granite ... it is closest to man made terazzo .... But still
> "a nice marble floor" ;)

agree.


regards, jr.

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Op 21-4-2021 om 15:47 schreef Mr:
> Getting closer indeed! Now it has much more scale variations. Credit
> (unwillingly :-P) deserved by Ive for showing us merits of the original files.
> It might appear one could still prefer Ive's restored original version for the
> single occurrences showed. At least its contrast curve could stay the reference.
> 
Yes, as reference certainly, in combination with what I can find on the 
internet I want to stress.

> But as you geologist said, its bigger scale is misleading. For having struggled
> to do something that stays consistent at various scales, I know that you're
> tackling something more demanding but keep hope, do not give up, try to reach an
> as pleasing color curve. Theoretically, it could even get better than the
> original as the new pov version can produce more nuances. I believe at this
> stage showing both the current one and a much closer up framed render would do
> it justice.
> 
indeed.

> *Saturation of the colors should be slighly more and brightness slightly less,
> but don't look at the picture straight out of the renderer, only after applying
> it the gamma above 1.8 and below 2.5. if your rendered frame display gamma
> doesn't do that. I would try playing either in very small amounts with the
> brilliance keyword. or switch to another shading model if they did get
> implemented since Uberpov? if they haven't the #brilliance shift kind of does
> that "shading model translation" (OrenNayar Blinn would have sigmas for various
> rocks well referenced I think).
> 
Yes, more tweaking needed here indeed, saturation and brightness. 
Display_Gamma is set as sRGB since the days of Clipka at least.

> *The specularity looks somewhat wrong sorry to be that vague: did you use
> specular or phong, because what I more clearly meant was that it looks like
> phong : too blurry.
> 
I don't/never use phong, only specular
> 
> Now it's just all bonus, though, the material feels really official includable
> level already!
> 
Thanks! :-)

> Thanks for your work !
> 
I am getting adicted! ;-)

-- 
Thomas

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Op 21-4-2021 om 15:15 schreef jr:
> hi,
> 
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Op 21-4-2021 om 13:56 schreef jr:
>>> note to Thomas: _please_ correct the spelling to 'mahogany'.
>>
>> I have been wondering about the spelling. After (again) assessing the
>> occurrence of both spellings on the net, it seems indeed that "Mahogany"
>> is the correct one.
> 
> perhaps also to do with accessing the net from the Netherlands vs the UK?  both
> Google and Wiktionary don't think much -- anything! -- of 'mohogany'.
> 
True here too but there are a couple from "commercial" sites in the US.

> 
>> I followed Daniel Mecklenburg's original (wrong) spelling from the start.
>>
>> Additional Names: Dakota Mahagony,Dakota Mahogany,Mahogany
>> Dakota,Mahogany Dakota America,Rushmore Mahogany,Select Mahogany,Sunset
>> Mahogany,Brown Velvet Mahogany,Whetstone Mahogany,American
>> Bouquet,Carnelian Granite    :-)
>>
>> see: {...}
>>
>> I shall correct but I wonder if I am not going to name it: "Dakota Red
>> Granite" instead.
> 
> do "mahogany granites" occur in places other than the Dakotas? if yes, I'd put
> the "Dakota Red" plus latin nomenclature with the by-variant "background" info.
>
Probably not. I suppose it is a local variation name. Remember: these 
are commercial names, not scientific.

> (and thanks for making change to spelling)
> 
Always happy to serve, sir. ;-)


-- 
Thomas

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Op 21-4-2021 om 15:12 schreef ingo:
> in news:web.608012f064981f5c79819d986cde94f1@news.povray.org jr wrote:
> 
>> "fake granite
> 
> 've been looking at this thread with half an eye only. I worked in the
> graphics industry for quite a while and one of my jobs was pattern
> designer & colorist. The one thing I learnt,
> 
> People want what they think looks like the real thing. Not what the real
> thing actually looks like.
>
How true!

> I have a colorised concrete floor in my house. The top layer has been
> ground off into the "grain". "What a nice marble floor" ... it looks more
> like a coarse granite ... it is closest to man made terazzo .... But still
> "a nice marble floor" ;)
> 
> https://ingoogni.nl/stuff/IMG_2021_04_21_0277_s.jpg with a nice line of
> light.
> 
> Ingo
> 

Oh lol! almost but not quite a granite. Nice terrazzo certainly. I have 
tiles on my floor with a "rock" print. They are all identical but 
complex enough to fool the eyes at first glance. However, how fake can 
you get!? I didn't choose them... ;-)

-- 
Thomas

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