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3 Aug 2024 16:25:47 EDT (-0400)
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From: Severi Salminen
Subject: Re: Velvet curtains?
Date: 3 Feb 2004 12:31:29
Message: <401fdaf1$1@news.povray.org>
Darren wrote:
> I'm looking to render some hanging velvet curtains, like you might see 
> in front of a stage at a theatre. I haven't any idea, however, where to 
> start with such a texture/shape. Are patches/splines the only way to 
> handle it?
> 
> I'm kind of looking for something where I could give it a bounding box, 
> say, and have it be the right size, rather than hand-crafting a specific 
> curtain for each size doorway I'm putting a curtain into, but I'll do 
> the latter if that's the only way.
> 
> Has anyone already done this and would be willing to give me hints or 
> even texture declarations?

I have not done it, but how about simply using a prism object? Define a 
spline and sweep it along a straight line. The spline defines how flat 
or wrinkled the curtain is and then you just sweep it to get correct 
curtain height. At least the curtains of the window next to me look like 
they can easily be modeled like this. But if the curtains are not freely 
hanging then you must use some other method.

Severi S.


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From: Gilles Tran
Subject: Re: Velvet curtains?
Date: 3 Feb 2004 18:36:32
Message: <40203080@news.povray.org>

news:401fd81e$1@news.povray.org...
> I'm looking to render some hanging velvet curtains, like you might see
> in front of a stage at a theatre. I haven't any idea, however, where to
> start with such a texture/shape. Are patches/splines the only way to
> handle it?
>
> I'm kind of looking for something where I could give it a bounding box,
> say, and have it be the right size, rather than hand-crafting a specific
> curtain for each size doorway I'm putting a curtain into, but I'll do
> the latter if that's the only way.
>
> Has anyone already done this and would be willing to give me hints or
> even texture declarations?

Velvet textures are quite angle-dependent and this is not supported in
regular POV-Ray. You need the angle of incidence pattern of MLPov
http://martial.rameaux.free.fr/mael/mlpov083.html for this.

In regular POV-Ray, this can be more or less faked using the slope pattern
if the objects are not too large (I've used the trick on small furry animals
but I don't know how it looks on velvet curtains).

#include "colors.inc"
#declare cam_location=-z*10;
#declare cam_look_at=0;
camera {
    location cam_location
    right     x*image_width/image_height
    look_at   cam_look_at
}
#declare Position=<4,0,0>;
light_source{<100,100,-200> White*2}
blob{
    threshold 0.6
    sphere{0,1.7,1 translate -y}
    sphere{0,1.7,1 translate x+y}
    sphere{0,1.7,1 translate -x+y}
    texture{
        slope {Position-cam_location,0,0.5}
        texture_map{
            [0.3 pigment{Red} finish{ambient 0 diffuse 0.3 specular 0.1
roughness 1/100}] // inner
            [1 pigment{Red} finish{ambient 0 diffuse 1 specular 0.1
roughness 1/100}] // outer
        }
    }
    translate Position
}


There's also a velvet-like texture here http://runevision.com/3d/povgoodies/

G.


-- 
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters


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From: Mike Williams
Subject: Re: Velvet curtains?
Date: 3 Feb 2004 22:44:08
Message: <58uGDCAbVCIAFw$g@econym.demon.co.uk>
Wasn't it Darren who wrote:
>I'm looking to render some hanging velvet curtains, like you might see 
>in front of a stage at a theatre. I haven't any idea, however, where to 
>start with such a texture/shape. Are patches/splines the only way to 
>handle it?
>
>I'm kind of looking for something where I could give it a bounding box, 
>say, and have it be the right size, rather than hand-crafting a specific 
>curtain for each size doorway I'm putting a curtain into, but I'll do 
>the latter if that's the only way.
>
>Has anyone already done this and would be willing to give me hints or 
>even texture declarations?

Simon Adameit produced some excellent media velvet textures and posted
them to povray.text.scene-files back in Feb 2002. You should be able to
find one of them at

http://news.povray.org/3c73d149@news.povray.org



-- 
Mike Williams
Gentleman of Leisure


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From: Tom Melly
Subject: Re: Velvet curtains?
Date: 4 Feb 2004 14:30:36
Message: <4021485c@news.povray.org>
"Darren" <dne### [at] sanrrcom> wrote in message
news:402044c6$1@news.povray.org...
>
> Anyway, thanks for the helpful advice and links and textures and all!

Also, take a look at Rune's fur texture (probably uses a similiar trick to
Gilles')

http://runevision.com/3d/povgoodies/

I used it to simulate the velvet on the cushions in this scene:

http://www.tomandlu.co.uk/webres/raytracing/gallery/pics/tmworsh.jpg
(http://tinyurl.com/2wkq4)


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From: Christopher James Huff
Subject: Re: Velvet curtains?
Date: 4 Feb 2004 19:36:37
Message: <cjameshuff-11FC30.19364704022004@news.povray.org>
In article <401fd81e$1@news.povray.org>, Darren <dne### [at] sanrrcom> 
wrote:

> I'm looking to render some hanging velvet curtains, like you might see 
> in front of a stage at a theatre. I haven't any idea, however, where to 
> start with such a texture/shape. Are patches/splines the only way to 
> handle it?

I once did a curtain with an isosurface...not very accurate, but fairly 
convincing.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: Dan P
Subject: Re: Velvet curtains?
Date: 4 Feb 2004 20:35:05
Message: <40219dc9$1@news.povray.org>
"Christopher James Huff" <cja### [at] earthlinknet> wrote in message
news:cjameshuff-11FC30.19364704022004@news.povray.org...
> In article <401fd81e$1@news.povray.org>, Darren <dne### [at] sanrrcom>
> wrote:
>
> I once did a curtain with an isosurface...not very accurate, but fairly
> convincing.

That sounds /cool/. How did you manage that!!? :-)


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From: "Jérôme M. Berger"
Subject: Re: Velvet curtains?
Date: 14 Feb 2004 15:00:48
Message: <402e7e70$1@news.povray.org>
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This answer could be a little late, but if it's not you might want to
take a look at the cloth simulator:
http://jeberger.free.fr/cloth/cloth.html

It should allow you to do this kind of thing pretty easily:
http://jeberger.free.fr/cloth/curtain.png

Jerome

PS: Hi everybody, long time no see...

Darren wrote:
| I'm looking to render some hanging velvet curtains, like you might see
| in front of a stage at a theatre. I haven't any idea, however, where to
| start with such a texture/shape. Are patches/splines the only way to
| handle it?
|
| I'm kind of looking for something where I could give it a bounding box,
| say, and have it be the right size, rather than hand-crafting a specific
| curtain for each size doorway I'm putting a curtain into, but I'll do
| the latter if that's the only way.
|
| Has anyone already done this and would be willing to give me hints or
| even texture declarations?
|
| Currently using 3.1, because I've not yet found anything I'm trying to
| do that I couldn't do in 3.1, but no good reason not to upgrade.
|
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