POV-Ray : Newsgroups : povray.binaries.scene-files : Dakota Red Granite macro - beta #1.2 Server Time
25 Jul 2021 12:12:41 EDT (-0400)
  Dakota Red Granite macro - beta #1.2 (Message 11 to 19 of 19)  
<<< Previous 10 Messages Goto Initial 10 Messages
From: Bald Eagle
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 24 May 2021 20:25:00
Message: <web.60ac4306c1167ed21f9dae3025979125@news.povray.org>
Also, maybe someone can hunt down a copy of this paper:
I couldn't find a copy anywhere (so far)

Modeling and Rendering of Heterogeneous Granular Materials: Granite Application
March 2007Computer Graphics Forum 26(1):66 - 79


Post a reply to this message

From: Thomas de Groot
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 25 May 2021 02:24:23
Message: <60ac9817$1@news.povray.org>
Op 25/05/2021 om 02:21 schreef Bald Eagle:
> Modeling and Rendering of Heterogeneous Granular Materials: Granite Application

I got no farther than this:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-8659.2007.00949.x

Pricey guys those editors! It is slowly changing with journals gradually 
becoming more "open access". However, the /big/ journal editors (like 
Wiley) are stalling of course...

-- 
Thomas


Post a reply to this message

From: ingo
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 25 May 2021 02:57:54
Message: <XnsAD355B31F3086seed7@news.povray.org>
in news:60ac9817$1@news.povray.org Thomas de Groot wrote:

> https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-8659.2007.00949.x

You are aware of Sci-hub? https://sci-hub.41610.org/

Ingo


Post a reply to this message

From: Thomas de Groot
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 25 May 2021 04:47:21
Message: <60acb999$1@news.povray.org>
Op 25/05/2021 om 08:57 schreef ingo:
> in news:60ac9817$1@news.povray.org Thomas de Groot wrote:
> 
>> https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-8659.2007.00949.x
> 
> You are aware of Sci-hub? https://sci-hub.41610.org/
> 
> Ingo
> 
I hadn't been! Thanks a lot indeed!

-- 
Thomas


Post a reply to this message

From: Bald Eagle
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 25 May 2021 06:00:00
Message: <web.60acc9f1c1167ed21f9dae3025979125@news.povray.org>
ingo <ing### [at] tagpovrayorg> wrote:

> You are aware of Sci-hub? https://sci-hub.41610.org/
>
> Ingo

Ugh - I was, casually.  Forgot about that.  Did the trick - thanks   :)
I dug up a few other papers, will see if they have anything that helps in the
current situation.

Thanks, Ingo


Post a reply to this message

From: Bald Eagle
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 25 May 2021 06:05:00
Message: <web.60accb12c1167ed21f9dae3025979125@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:

> Maybe the best sslt test-bed would be a back-lit wedge of material, much like
> what Ansel Adams would do with the Zone System when calibrating negatives and
> prints.

This is a thin prism (0 to 0.1) with a single point light behind the left edge.

I'm wondering if eval_pigment could act as a way to guide the result?


Post a reply to this message


Attachments:
Download 'granitessltwedge.png' (91 KB)

Preview of image 'granitessltwedge.png'
granitessltwedge.png


 

From: Thomas de Groot
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 26 May 2021 03:28:27
Message: <60adf89b$1@news.povray.org>
Op 24-5-2021 om 19:29 schreef Bald Eagle:
> Now that it's looking good, I'd say it's time to think.... 
Yeah! Still need to answer these comments. I have a bunch of RL writings 
to do presently. However, I have some ideas and shall not forget. Just 
in need of time...

-- 
Thomas


Post a reply to this message

From: Bald Eagle
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 26 May 2021 05:35:00
Message: <web.60ae15f4c1167ed21f9dae3025979125@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> I have a bunch of RL writings to do presently.


I know.  I'm busy for next 2-3 days as well, but it's all still kicking around
up there.


Post a reply to this message

From: Thomas de Groot
Subject: Re: Dakota Red Granite macro - beta #1.2
Date: 28 May 2021 11:03:55
Message: <60b1065b$1@news.povray.org>
Op 24-5-2021 om 19:29 schreef Bald Eagle:
> There should definitely be a parameter passed to the macro for width of the
> vein, and frequency of occurrence.
> 
Have to look into this.

> Now that it's looking good, I'd say it's time to think about how to pass
> alternative color maps into the texture - both to model other granite types, as
> well as use the change to spot something in the current implementation that
> might be hiding, but a different color scheme might bring out.
> 
My choice is this (See also the latest beta: Granite_21_beta_1.4.mcr 
below) is:
- a master macro: Granite_21 ()
- include files containing the necessary arrays for the different 
granites, and to be declared by the user and read by the macro.
- at this moment (also default) there is DakotaRedGranite.inc

> Piggybacking on that idea, there should be some triggerable material attribute
> data output to #debug with numbered map entries, and then we could have a
> mechanism to pass in a color for a single entry on-the-fly.  Then it would be
> easy to plug the macro calls into a loop and render a ton of different samples
> when tweaking a new material.
> 
Possibly the present bata can do this. Not tested.

> The macro should also top up my coffee or G&T while I'm working on a scene,
> depending on the value of a required parameter.  :D
> 
The coffee parameter is not yet available.

> 
>> I am trying to get a grip on how to
>> tweak the translucency parameter.
> 
> The way clipka explained it that the translucency color is geared toward what
> color you want the sslt effect to take on as it percolates through the material.
>   So for skin, where the blood will add a red color and absorb the blue and
> green, you set the color to a red-channel dominant rgb vector.
> 
Absolutely.

> Maybe the best sslt test-bed would be a back-lit wedge of material, much like
> what Ansel Adams would do with the Zone System when calibrating negatives and
> prints.
>
Yes. I used the bunny...

> Clipka also recommended in one thread to overlay the sslt texture layer with
> something else and maybe(?) he specifically said to only set the sslt in the
> lower layer...  I'd have to search and pull it up.
> 
That is definitely what one should do as far as my tests show.

-- 
Thomas


Post a reply to this message

<<< Previous 10 Messages Goto Initial 10 Messages

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.