Op 16-4-2021 om 09:36 schreef Kenneth:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>>
>> I have come to the conclusion that granites21.inc is /based on/
>> granites.inc by Daniel Mecklenberg and not an exact reproduction of his
>> code. If we want those, we need to render the original file separately,
>>    with the initial conditions like Ive and you have done.
>>
> Yes, I agree. And in my personal opinion, the gamma 1.0 'look' is most likely
> what was intended, more or less-- based on my trust of your own knowledge of
> granites, and also the original comments by Daniel M, who seemed to know about
> the subject himself. It would surprise me if he did run his textures with a
> 2.2-gamma and accepted the result-- because I would assume that "North American
> Pink granite" is a well-known and 'standard' type of rock, agreed on by
> geologists.  Not like 'political viewpoints', ha.
> 
> 
Lol! My thoughts entirely. I assume that Daniel Mecklenburg intended his 
textures to be used with an added scale closely related to the 
/dimensions/ of the supporting object where a 10cm wide cube in one 
scene would need a different scale than a 10m wide stone wall in another 
scene. Caveat: if used in the same scene, both objects would of course 
need the same scale! I would argue that, by itself, any POV-Ray texture 
is "dimensionless" and needs a known support in order to be scaled 
accordingly.

I assume that the name "North American Pink" is the commercial name. As 
a geologist, I would call it a 'granodiorite' probably. The same goes 
for the other granites textures which I have been able to trace in the 
Real World.

In any case, as 'simple' users, lets be and remain creative! Also in the 
rgb/srgb matter (ouch! I did it again!). We have a saying here: "buiten 
de lijntjes kleuren" which translates as "colouring outside the lines 
(or the boundaries)" and meaning "breaking the rules" in particular 
concerning the creative process, but also applied to scientific 
research. It promotes serendipity without any doubt imo.

-- 
Thomas

Post a reply to this message

Am 4/16/2021 um 10:21 schrieb Thomas de Groot:
> Op 16-4-2021 om 09:36 schreef Kenneth:
>> Thomas de Groot <tho### [at] degrootorg> wrote:
>>>
>>> I have come to the conclusion that granites21.inc is /based on/
>>> granites.inc by Daniel Mecklenberg and not an exact reproduction of his
>>> code. If we want those, we need to render the original file separately,

>>>
>> Yes, I agree. And in my personal opinion, the gamma 1.0 'look' is most 
>> likely
>> what was intended, more or less-- based on my trust of your own 
>> knowledge of
>> granites, and also the original comments by Daniel M, who seemed to 
>> know about
>> the subject himself. It would surprise me if he did run his textures 
>> with a
>> 2.2-gamma and accepted the result

I'm can assure you that in 1996 absolutely nobody did use assumed_gamma 
1.0 for reasons that are actually quite obvious even if you do not 
understand them.
On the other hand my guess would be them someone with the pseudo "Code 
Warrior" (and its implied reference to Mel Gibson) did not use a toy 
operating system like Windows 95 which means he did use assumed_gamma 
1.8 as a consequence.


>> because I would assume that "North 
>> American
>> Pink granite" is a well-known and 'standard' type of rock, agreed on by

>>
>>
> Lol! My thoughts entirely. I assume that Daniel Mecklenburg intended his 
> textures to be used with an added scale closely related to the 
> /dimensions/ of the supporting object where a 10cm wide cube in one 
> scene would need a different scale than a 10m wide stone wall in another 
> scene. Caveat: if used in the same scene, both objects would of course 
> need the same scale! I would argue that, by itself, any POV-Ray texture 
> is "dimensionless" and needs a known support in order to be scaled 
> accordingly.
> 
> I assume that the name "North American Pink" is the commercial name. As 
> a geologist, I would call it a 'granodiorite' probably. The same goes 
> for the other granites textures which I have been able to trace in the 
> Real World.
> 
> In any case, as 'simple' users, lets be and remain creative! Also in the 
> rgb/srgb matter (ouch! I did it again!). We have a saying here: "buiten 
> de lijntjes kleuren" which translates as "colouring outside the lines 
> (or the boundaries)" and meaning "breaking the rules" in particular 
> concerning the creative process, but also applied to scientific 
> research. It promotes serendipity without any doubt imo.
> 

Well, my understanding was that this is not just about this particular 
granite file, but about a correct way to convert in general old textures 
from times were *never* assumed_gamma = 1.0 was used.

Obviously this is not the case, sorry for this misunderstanding on my 
part, but frankly you should have said so in the first place and should 
not have added a bunch of buzz words borrowed from color science into 
your header where these words make no sense at all.

So I did completely waste my time here and it seems you did not even 
bother to look at my code - as all I hear is just about comparing 
images. So here is a final image from me also produced with my code but 
with some more educated "guesses" to tweak one user parameter - based on 
the image you did show.

My conclusion: my first thought was right, so please do not mention me 
in any of your files, seriously I mean it.

No need to bother with a reply I'm outa here

so long - Ive

Post a reply to this message

oops, the image...

Post a reply to this message

Attachments:
Download 'nap.png' (496 KB)

Preview of image 'nap.png'

"Kenneth" <kdw### [at] gmailcom> wrote:

> Yes, the 'Cornell box' scene is in SCENES/RADIOSITY (I had to hunt for it.)

I peeked there, but it was the most cursory of late-night scans.  I missed it.
IIRC, it was a complicated scene that had a lot of code that I didn't
understand.

I was not suggesting the idea to show any true colors, but as a means of having
an absolute standard environment in terms of lighting, environment, and scale to
compare "side-by-side" two objects and their textures.

That way any differences are coming from the texture definition and any
quibbling and misunderstandings about lighting, object size, etc can be [mostly]
avoided.

Scene variants can have different light sources for highlighting, etc.
Not sure what a good object would be - a sphere with radial normal map?


And I do wish that kids like you and that DeGroot hoodlum would just GROW UP and
have a little maturity.  You spoiled children clearly flaunt your privilege and
brazenly appropriate the cultural heritage of the POV-Ray late 90's.  It's
shameful - and offensive.  "HOW DARE YOU!"  You're probably even using the wrong
surface modification and not the New Normal!  Rather than demonstrate how we as
a people have evolved and advanced civilization through enlightenment and
diversity, you prattle on in your ego chamber about inconsequential social
constructs that are devoid of relevance to the feelings about someone you've
never met and probably haven't ever heard of before now.  How then can we have
peace?  If you had the least care in the world about notional justice, you'd
burn down the city around you to show it - maybe even plowing through a crowd of
quartz and feldspar lovers with your van in the process.  Allahu Code Warrior!
Perhaps if you two were even woke enough to confront your own [m]in[eral]grained
biases, you'd loot a sto[n]re or two and get a REAL computer with a serious
operating system - like _Apple_.  Then we could take back the means of
production from the Upper Class, smash capitalism, strike a blow for the
underprivileged and oppressed, AND fight Climate Change all in one go!
Then under Full Communism, you could do things with your rightfully
redistributed property the One Right Way and we could - finally - have unity.

(Hey - - - Do you think we could code the granites in Unity and see what they
look like there ... ?)

War is Peace!
Freedom is Slavery!
and Ignorance is Strength.

Contemplate your sins against Big Brother Ive - and _be ashamed_.



Whoops - there goes my alarm - I've [sic] got to go take another Dried Frog Pill
and watch "Beyond Melodrome" ....  Anyone else around here need one?

Post a reply to this message

Op 16-4-2021 om 13:13 schreef Bald Eagle:
> Whoops - there goes my alarm - I've [sic] got to go take another Dried Frog Pill
> and watch "Beyond Melodrome" ....  Anyone else around here need one?
> 
> 

  I thought so this morning. Uncle Bill was looking a little green about 
the eyes and jumping up and down in the backyard mumbling to himself 
about... what was it...? a Cornell Box!? Probably meant the Cornflake 
Box; which is empty by the way. Your turn Ken to go down to the shop 
today. And don't forget the beer! but keep it out of sight of uncle 
Bill; you know what happened last time.

-- 
Thomas

Post a reply to this message

Op 16-4-2021 om 11:28 schreef Ive:
> So I did completely waste my time here and it seems you did not even 
> bother to look at my code - as all I hear is just about comparing 
> images. So here is a final image from me also produced with my code but 
> with some more educated "guesses" to tweak one user parameter - based on 
> the image you did show.

Not even had the time to seriously look at your code, which I said I 
appreciated indeed. I have also a life besides POV-Ray and your comments 
need time to get digested seriously and commented on. Have a little 
patience, please?

> 
> My conclusion: my first thought was right, so please do not mention me 
> in any of your files, seriously I mean it.

Well... as you wish. No need to get angry. Have you never learned to 
take things in a relaxed way? My god, we use POV-Ray for our /pleasure/ 
or don't we? At least that is my philosophy.

> 
> No need to bother with a reply I'm outa here
> 
> so long - Ive
> 

Sorry to see you go...

-- 
Thomas

Post a reply to this message

Op 14-4-2021 om 18:00 schreef Alain Martel:

> One thing that can be done with layered textures with a finish in more 
> than one is to simulate varnished metals.
> 
> Have the base texture with metallic highlights and reflection, while the 
> top texture is transparent with fresnel highlights and reflection. Just 
> need to add an interior for the ior.
> 
> The rendered image is quite similar to actual varnished metal.

To tell the truth, I do not find this easy. I looked up the rules Clipka 
put forward (see attached pdf) and applied those as well as I was able 
to a granite texture (see attached image and the code below). I find the 
result too reflective and really difficult to manage correctly. The hue 
changes dramatically with changes to the reflection value or the 
specular albedo block. I need some help here. Thanks!

//start code
   #local Fudge = 1.9;
   #declare T1_MohoganyPol =
   texture {
     pigment {
       granite
       //turbulence 0.4
       color_map {
         [0.00 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<not_0, 
not_0, not_0>))]
         [0.25 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.059, 
0.059, 0.059>))]
         [0.25 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.086, 
0.027, 0.059>))]
         [0.35 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.118, 
0.118, 0.078>))]
         [0.35 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.200, 
0.137, 0.110>))]
         [1.00 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.769, 
0.329, 0.298>))]
       }
       scale 0.1 //0.8
     }
     /*finish {
       diffuse 0.8
       brilliance 1.5
       specular 0.9
       roughness 0.005
     }*/
     finish {
       diffuse albedo 0.01*(1-Fudge) brilliance 1.5
       specular albedo 0.8*Fudge roughness 0.001
       metallic on
       reflection {0.8 metallic on}
     }
   } //texture

   #declare T2_MohoganyPol =
   texture {
     pigment {
       granite
       turbulence 0.2
       color_map {
         [0.00 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.200, 
0.200, 0.200>)) transmit 0.149]
         [0.25 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<0.200, 
0.200, 0.200>)) transmit 0.949]
         [0.25 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<1.000, 
1.000, 1.000>)) transmit 1.000]
         [1.00 ColourSat(SatBoost, BrightBoost, scRGB_to_sRGB(<1.000, 
1.000, 1.000>)) transmit 1.000]
       }
       scale 0.3
       translate <20.0, 20.0, 33.0>
       rotate <0.3, 0.2, 0.0>
     }
     /*finish {
       diffuse 0.8
       brilliance 1.5
       specular 0.9
       roughness 0.005
     }*/
     finish {
       diffuse albedo 0.8*(1-Fudge) brilliance 1.5
       specular albedo 0.2*Fudge roughness 0.001
       fresnel on
       reflection {0.2 fresnel on} conserve_energy
     }
   } //texture

   #declare MohoganyPol_1 = texture {T1_MohoganyPol}

   #declare MohoganyPol_2 =
   material {
     interior {ior 1.5}
     texture {T1_MohoganyPol}
     texture {T2_MohoganyPol}
   } //material
//end code

-- 
Thomas

Post a reply to this message

Attachments:
Download 'mohoganypol2-2.jpg' (83 KB) Download 'clipkas finish 1.pdf' (66 KB)

Preview of image 'mohoganypol2-2.jpg'

Thomas de Groot <tho### [at] degrootorg> wrote:
I find the
> result too reflective and really difficult to manage correctly. The hue
> changes dramatically with changes to the reflection value or the
> specular albedo block.

Whoa.  That's super shiny.  It looks like polished marble dipped in
polyurethane.

It took me while of looking over the surface to understand that what I thought
might be some weird artefact is actually the reflection of the edge of your
curved plane and the sky_sphere.

This would be a great texture to apply to make wet granite - maybe a bird bath
or a fountain or something.  I'm sure it would look interesting to texture an
isosurface with this and apply a few off-center radial sine-waves.

Post a reply to this message

Ive <ive### [at] lilysoftorg> wrote:

>
> I'm can assure you that in 1996 absolutely nobody did use assumed_gamma
> 1.0 for reasons that are actually quite obvious even if you do not
> understand them.

Gee, I guess I don't, not being blessed with your obviously superior and
all-seeing knowledge.

>
> Well, my understanding was that this is not just about this particular
> granite file, but about a correct way to convert in general old textures
> from times were *never* assumed_gamma = 1.0 was used.
>
> Obviously this is not the case, sorry for this misunderstanding on my
> part but frankly you should have said so in the first place and should
> not have added a bunch of buzz words borrowed from color science into
> your header where these words make no sense at all.

Gee, an actual half-baked apology? From Your Highness?! (with a dose of further
insults, of course) Wow. I'll bet you choked on it, trying to get it out.
>
> So I did completely waste my time here...

Gee, that's sad.
>
> My conclusion: my first thought was right, so please do not mention me
> in any of your files, seriously I mean it.

Gee, that sounds SERIOUS. You mean it! (...or else?...) Personally, I would pay
no attention to such egotistic claptrap. It actually makes me laugh. And if you
felt insulted and wronged and that your *orders* were not being paid attention
to, you would be welcome to take your case to the International Criminal Court
of Justice to seek redress...if they don't laugh too, and kick you out of the
building.

>
> No need to bother with a reply

Yes Sir, if you say so Sir.

 I'm outa here

Gee, that's sad too. I guess you'll be flying back to Mount Olympus now, to be
among your fellow Gods. Well, don't let the door slam on your way out!
*Somehow*, the rest of us will manage to get along...
>
> so long - Ive

Send us a postcard from On High.

------
But I still like your IC app; I'm not yet going to tear it from my computer and
burn its bytes in a fit of childish temper...like you have displayed.

You may take your toys and go home now.

Post a reply to this message

"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Kenneth" <kdw### [at] gmailcom> wrote:
>
> > Yes, the 'Cornell box' scene is in SCENES/RADIOSITY (I had to hunt for it.)
>
> I peeked there, but it was the most cursory of late-night scans...

What?! You only *peeked* at it??  No No No, that is NOT the 'POV-ray way'. The
rules are clearly spelled out in chapters 7,43, and 129 of the 'POV-ray
Behavior' manual. Don't tell me you haven't read them??
>
>
> And I do wish that kids like you and that DeGroot hoodlum would just
> GROW UP and have a little maturity.  You spoiled children clearly flaunt
> your privilege...

SPOILED?! Oh, you mean, because of that $50 million I inherited when I was 2
months old? Naw, I've always been the same lovable, cuddly, ever-so-pleasant
fellow that I was before then. I think.

> ...you'd burn down the city around you to show it - maybe even plowing
> through a crowd of quartz and feldspar lovers with your van in the process.

Personally, I would prefer olivine and soapstone lovers...they always irritate
me...

Post a reply to this message