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.

Post a reply to this message

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

Post a reply to this message

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

Post a reply to this message

Thomas de Groot <tho### [at] degrootorg> wrote:
> 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

Also, sorry , but ignore the part of my comment about brightness or saturation,
I am not sure of any such thing until I see more close ups or render them myself
if I get some time. However, to push further on the scale variation, I thing the
biggest salmon colour splotches are still  too frequent when looking at
reference photo don't they occur slightly less frequently / more distant from
each other?  ... but your eye should be more expert about this.

Post a reply to this message

Op 21/04/2021 om 10:48 schreef Paolo Gibellini:
> Thomas de Groot wrote on 19/04/2021 13:56:
>> Op 19-4-2021 om 11:57 schreef Paolo Gibellini:
>>> Thomas de Groot wrote on 16/04/2021 08:46:
>>>> [snip]>
>>>
>>> Regarding marbles, in my area it was often used marble containing 
>>> ammonites, does this seem an interesting challenge to you?
>>> See the picture as reference.
>>>
>>> Paolo
>>
>> A challenge? It would be a very interesting to do indeed. Not 
>> immediately as I want to complete the granites first, but it is /an 
>> offer I cannot refuse/ ;-)
>>
> 
> Honestly I used the word challenge in a generic way, but a real 
> challenge could be interesting, it would add more content to the inc files.
> 
> When you are done...
> 

I did understand it in a generic way indeed. It is a challenging task to 
do.

This particular marble would have to be tackled with an 
*object_pattern*. Never used them seriously, but I guess it would be the 
way to go. Want to try? :-)

-- 
Thomas

Post a reply to this message

Op 21/04/2021 om 17:06 schreef Mr:

> Also, sorry , but ignore the part of my comment about brightness or saturation,
> I am not sure of any such thing until I see more close ups or render them myself
> if I get some time. However, to push further on the scale variation, I thing the
> biggest salmon colour splotches are still  too frequent when looking at
> reference photo don't they occur slightly less frequently / more distant from
> each other?  ... but your eye should be more expert about this.
> 
Anyway, your comments on brightness and saturation are well taken. They 
need a bit of extra attention imo, even if correct. The whole use of 
finish is still under my scrutiny.

Scale variation: yes, you are absolutely right and I want to get a 
better control on the distribution of the different grains. What in 
particular is missing in this "matrix" is quartz, besides the 
salmon-coloured feldspars. Literature gives the (varying) proportions of 
each and can serve as a guide.

This is going to be the next step now for me with this test granite. As 
soon as I get something working I shall post the code for everybody to 
test and shoot on (if they feel the urge).

-- 
Thomas

Post a reply to this message

hi,

Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 21-4-2021 om 15:15 schreef jr:
> > ...
> > Google and Wiktionary don't think much -- anything! -- of 'mohogany'.
> >
> True here too but there are a couple from "commercial" sites in the US.
> ...
> Probably not. I suppose it is a local variation name. Remember: these
> are commercial names, not scientific.

had not thought of/forgotten they're trade names.  will try + remember.


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

</grin>


> I am getting adicted! ;-)

</more-grinning>


regards, jr.

Post a reply to this message

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.
> 
The sad thing is that Ive made a very valuable contribution to this 
project with his NAP.pov file. As soon as I got the time to browse 
through it, I could see that. But before I could even properly comment, 
he got impatient, pissed-off, uninterested in the first place with 
POV-Ray, I don't even know what or why, and just dropped out. I can say 
at this stage that his file is the perfect vehicle to re-render the 
original granites by Daniel Mecklenburg. With some tweaking (adding an 
extra scale for instance) they even begin to look like granites. ;-)

There are parameters Ive used in NAP.pov of which I had not even be 
aware of, so I learned a number of new things about POV-Ray, and that 
progress is vital/fundamental.

-- 
Thomas

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