POV-Ray : Newsgroups : povray.binaries.programming : model of a scene Server Time: 14 Dec 2018 10:14:41 GMT
  model of a scene (Message 1 to 3 of 3)  
From: Le Forgeron
Subject: model of a scene
Date: 4 Aug 2002 14:42:13
Message: <3D4D3A2C.633607A4@free.fr>
Seems to be the right group, at least I hope so.

I had too much time waiting for the 3.5, so I played with 3.1 ...

I tried to represent a scene with some UML goodies (not strictly sticking to the
standard), and I'm wondering if it wouldn't be better to replace the layered_texture
(in Cyan in the picture) with a layered_pigment (in Green), because it is rather
how it works in reality.

Also, it's seems that a patterned_finish is somehow missing, even if it can currently
be done using the patterned_texture. (The green part attached to the finish does
not exist).
Wouldn't it be simpler to restrict the control at the lowest level, or
is there a real gain to also have a patterned_texture ?

Any thought on these ?
Any interest ?
Is there any one reading ?

P.S.: Do not pay attention to the yellow tags, they are just the parts which
are the most likely to get extensions whenever someone make a patch.
-- 
Non Sine Numine
http://grimbert.cjb.net/
Etiquette is for those with no breeding;
fashion for those with no taste.


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From: honnza
Subject: Re: model of a scene
Date: 3 Oct 2007 22:00:01
Message: <web.47040fd7c2e1f34da9ce4df50@news.povray.org>
Le Forgeron <jgr### [at] freefr> wrote:
> Seems to be the right group, at least I hope so.
>
> I had too much time waiting for the 3.5, so I played with 3.1 ...
>
> I tried to represent a scene with some UML goodies (not strictly sticking to the
> standard), and I'm wondering if it wouldn't be better to replace the layered_texture
> (in Cyan in the picture) with a layered_pigment (in Green), because it is rather
> how it works in reality.

If you cover some parts of a mirror with paint, you don't get the mirror
finish on the paint. Rather you get one texture of pure reflection partly
covered with little reflecting green surface. This is what you get with
layered & patterned textures.
If you want a common finish to multiple textures you should use a clear
texture over multiple pigment only textures because it is rather how it
works in reality :-) (a thin film on the surface is what usually does
reflect)
But I agree layered pigments might come in handy though layered textures do
exactly the same (apart from metallic, I presume). One warning, though:
multiple textures each containing a finish get their finishes evaluated
separately, tracing one ray multiple times


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From: Le Forgeron
Subject: Re: model of a scene
Date: 4 Oct 2007 21:06:38
Message: <470555de$1@news.povray.org>
Thanks you for your interest, it's just a more than five years old
picture... and you're the first to answer.

Le 03.10.2007 23:55, honnza nous fit lire :

> If you cover some parts of a mirror with paint, you don't get the mirror
> finish on the paint. Rather you get one texture of pure reflection partly
> covered with little reflecting green surface. This is what you get with
> layered & patterned textures.

Wouldn't it be simpler to handle the finish and pigments separatly ?
Unless you have a subsurface-scatering model (and you'd better fake
it than tracing all these rays), I do not see the point of having
layered finish: only the topmost one is the finish you will ever see.

It's a bit like normal, what would be the sense of layered normal ?
(averaged or whatever patterned, I can understand, but layered
normal is such a strange idea...)

> If you want a common finish to multiple textures you should use a clear
> texture over multiple pigment only textures because it is rather how it
> works in reality :-) (a thin film on the surface is what usually does
> reflect)

Or you can duplicate the finish everywhere, but what is your point ?

> But I agree layered pigments might come in handy though layered textures do
> exactly the same (apart from metallic, I presume).

They do the same, but layered textures just seems so wrong in the
scope that textures have reached.

> One warning, though:
> multiple textures each containing a finish get their finishes evaluated
> separately, tracing one ray multiple times
> 
I do not understand that.

-- 
The superior man understands what is right;
the inferior man understands what will sell.
-- Confucius


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