POV-Ray : Newsgroups : povray.newusers : Strang texture behavior Server Time
5 Sep 2024 16:22:48 EDT (-0400)
  Strang texture behavior (Message 1 to 8 of 8)  
From: Remco Poelstra
Subject: Strang texture behavior
Date: 27 Feb 2000 16:13:59
Message: <38B9E8B4.BC3C0EE8@home.nl>
Hi,

I've created a very simple house, but the texture is strange on one site
(like it is scaled).
Here is a part of the code (just enough to see the problem):
____________________________________________________________
camera { 
    location < 0, 2, -25>
    look_at  <0,3,0>
    rotate y*90
}         
                 
light_source  { <100, 100, -100>
    color rgb 1
    rotate y*90
}


#declare Boerderij =
difference {
    box { < -4, 0, -2>, <  4, 4, 2>      
	texture {
	    pigment { brick
		scale 0.1
	    }
	}
    }
    box { <-3, 0, -2.0001>, <-1,  3,  3>        
	texture {
	    pigment { rgb 0 }
        }
    }
    box { < 0, 1, -2.0001>, < 3, 3, -1.99999>
	texture {
    	    pigment { rgb <0,0,1> }
        }
    }     
rotate <0, -90, 0>
scale <2, 2, 2>
}

object { Boerderij }
______________________________________________________________________

I hope someone can help me.

Remco Poelstra


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From: David Wilkinson
Subject: Re: Strang texture behavior
Date: 27 Feb 2000 18:29:17
Message: <opcjbssuevq8i4kaad5kuim6354mcifj1q@4ax.com>
On Sun, 27 Feb 2000 22:17:08 -0500, Remco Poelstra <rjp### [at] homenl> wrote:

Hi Remco

I have also had problems with the brick pattern.  You seem to found a definite bug. 
If
you change your scaling factor very slightly everything is OK. For instance if you
scale
the pigment by 0.102 it's OK, but it goes wrong with scale 0.101.  Similarly if you
use
scale 0.099 it's wrong, but 0.098 is OK.

I haven't gone any further than this, but to summarise, it appears that scaling
factors
between 0.098 and 0.102 give an incorrect pattern of bricks.
So just change your scale slightly and it will look reasonable.

e.g.

......	   
#declare Boerderij =
difference {
    box { < -4, 0, -2>, <  4, 4, 2>      
	texture {
		 pigment { brick
		scale 0.102
	    }
	}
    }
...........

I hope this helps
----------------------------
dav### [at] cwcomnet
http://www.hamiltonite.mcmail.com
----------------------------


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From: Chris Huff
Subject: Re: Strang texture behavior
Date: 27 Feb 2000 19:38:46
Message: <chrishuff_99-EE7AA4.19401627022000@news.povray.org>
In article <38B9E8B4.BC3C0EE8@home.nl>, Remco Poelstra 
<rjp### [at] homenl> wrote:

> I've created a very simple house, but the texture is strange on one site
> (like it is scaled).

I think the brick pattern is designed to be done in the xy plane and 
rotated/translated to position. You will have to texture each side of 
the wall separately, using separate objects for each wall, if you want 
to continue using the brick pattern. I usually find it inadequate for 
making brick walls, and model the bricks as separate objects using loops.

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/


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From: Remco Poelstra
Subject: Re: Strang texture behavior
Date: 28 Feb 2000 13:06:22
Message: <38BB0E3B.D47B677A@home.nl>
David Wilkinson wrote:
> I hope this helps
> ----------------------------
Yes, everything works fine now, thanks

Remco


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From: Remco Poelstra
Subject: Re: Strang texture behavior
Date: 28 Feb 2000 13:10:43
Message: <38BB0F3D.80773554@home.nl>
Chris Huff wrote:
> 
> In article <38B9E8B4.BC3C0EE8@home.nl>, Remco Poelstra
> <rjp### [at] homenl> wrote:
> 
> > I've created a very simple house, but the texture is strange on one site
> > (like it is scaled).
> 
> I think the brick pattern is designed to be done in the xy plane and
> rotated/translated to position. You will have to texture each side of
> the wall separately, using separate objects for each wall, if you want
> to continue using the brick pattern. I usually find it inadequate for
> making brick walls, and model the bricks as separate objects using loops.
> 
I have once tried to make the roof of a temple of real tiles, but it
needed 136 Mb of memory to parse. So I'm not going to do that again. :-(
And the brick pattern is good enough for the animation I'm creating.

Remco


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From: Chris Huff
Subject: Re: Strang texture behavior
Date: 28 Feb 2000 15:50:33
Message: <chrishuff_99-E038CB.15520328022000@news.povray.org>
In article <38BB0F3D.80773554@home.nl>, Remco Poelstra 
<rjp### [at] homenl> wrote:

> I have once tried to make the roof of a temple of real tiles, but it
> needed 136 Mb of memory to parse. So I'm not going to do that again. :-(

136MB...how many tiles did this roof have?!?

A couple possible ways I can think of to get around this:
1: Use mesh objects for the bricks. Since you probably aren't going to 
use CSG on them, they should work fine, and meshes can use memory more 
efficiently when you have multiple copies of the same mesh.

2: Use an isosurface. It should be possible, without too much effort, to 
make a row, or an entire wall, out of a single isosurface object. This 
has the advantages of being very flexible and efficient in terms of 
memory, but would require some knowledge of math and the isosurface 
object, as well as an unofficial version supporting the isosurface(like 
MegaPOV). It might also render considerably slower.


> And the brick pattern is good enough for the animation I'm creating.

In many cases it would be more efficient to use the brick pattern, in 
those scenes only detail-fanatics like me would use separate bricks. :-)

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/


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From: Remco Poelstra
Subject: Re: Strang texture behavior
Date: 29 Feb 2000 11:12:32
Message: <38BC450C.90BF5951@home.nl>
Chris Huff wrote:
> 
> In article <38BB0F3D.80773554@home.nl>, Remco Poelstra
> <rjp### [at] homenl> wrote:
> 
> > I have once tried to make the roof of a temple of real tiles, but it
> > needed 136 Mb of memory to parse. So I'm not going to do that again. :-(
> 
> 136MB...how many tiles did this roof have?!?

Because I had only memory for calculating one side of the roof, there
were 34300 tiles.
After completing my current animation, I'll restart the temple with mesh
objects or an isosurface

Thanks for the tips.

Remco


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From: Brendan Hurley
Subject: Re: Strang texture behavior
Date: 16 Mar 2000 15:09:02
Message: <38D13F92.BF245080@saber.net>
Dear Remco and Folks,
[snip]
> I have also had problems with the brick pattern.  You seem to found a definite bug. 
If
> you change your scaling factor very slightly everything is OK.
[snip]

I second that opinion.  I have had this problem in my current problem: a
brownstone apt building.  I think my scaling was a bit higher, but the
weird side-effect still occurred.

Blessings,
          Brendan

-- 
Michael Brendan Hurley
http://www.geocities.com/mbrendanh/
http://www.saber.net/~mbhcgc/
mbh### [at] sabernet


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