POV-Ray : Newsgroups : povray.beta-test : bug - interpolate 2 Server Time
2 Jul 2024 10:52:38 EDT (-0400)
  bug - interpolate 2 (Message 1 to 5 of 5)  
From: Rafal 'Raf256' Maj
Subject: bug - interpolate 2
Date: 29 Apr 2004 21:08:35
Message: <Xns94DB1FBCC42DAraf256com@203.29.75.35>
It looks like a real bug this time, new to 3.6.beta4.win32, NOT present in 
3.5.win32

Using interpolate 2 with density_file gives strange results.
Value 2 is invalid (should be 0 or 1).
Any other value Ive tested (3,4,5) results in no image at all.

Value 2 results in strange pixelized image (worse quality then without any 
interpolation).

Code:

// bug found by Rafal Maj raf256.com
// strange effect when using illegal interpolate 2 for density file
// confirmed PRESENT in: PovRay 3.6.beta4.win32
// confirmed   NOT   in: PovRay 3.5.win32
// render with any options, i.e.: +w640 +h480 +a0.02 +am2 +ar2 +fn

box { 0, 1
  pigment { color rgbt 1 }
	interior {
		media {  emission 3
	    density { density_file df3 "spiral.df3" 
        interpolate 2 // <------- illegal, should be 0 or 1 !
			}
	  }
	}
	hollow translate z*1-.5
}

image in .b-t.binaries





-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics


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From: Francois Labreque
Subject: Re: bug - interpolate 2
Date: 29 Apr 2004 22:02:29
Message: <4091b3b5$1@news.povray.org>
Program ended abnormally on 29/04/2004 21:08, Due to a catastrophic Rafal 
'Raf256' Maj error:

> It looks like a real bug this time, new to 3.6.beta4.win32, NOT present in 
> 3.5.win32
> 
> Using interpolate 2 with density_file gives strange results.
> Value 2 is invalid (should be 0 or 1).
> Any other value Ive tested (3,4,5) results in no image at all.
> 
> Value 2 results in strange pixelized image (worse quality then without any 
> interpolation).
> 

I disagree.  This is quite an interesting effect!  ;-)

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   videotron.ca  */}camera{orthographic location<6,1.25,-6>look_at a }


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From: Rafal 'Raf256' Maj
Subject: Re: bug - interpolate 2
Date: 29 Apr 2004 22:16:23
Message: <Xns94DB2B3B35F67raf256com@203.29.75.35>
fla### [at] videotronca news:4091b3b5$1@news.povray.org

>> Value 2 results in strange pixelized image (worse quality then
>> without any interpolation).

(btw, and interpolate 2 is about x5 times slower then trilinear 
interpolation!)

> I disagree.  This is quite an interesting effect!  ;-)

You work for microsoft, don't You ;) ?

-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics


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From: Thorsten Froehlich
Subject: Re: bug - interpolate 2
Date: 3 May 2004 02:55:15
Message: <4095ecd3@news.povray.org>
In article <Xns94DB1FBCC42DAraf256com@203.29.75.35>, "Rafal 'Raf256' Maj" 
<spa### [at] raf256com> wrote:

> Using interpolate 2 with density_file gives strange results.
> Value 2 is invalid (should be 0 or 1).

No, it is valid in 3.6 and should give you tricubic interpolation.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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From: Rafal 'Raf256' Maj
Subject: Re: bug - interpolate 2
Date: 3 May 2004 11:05:30
Message: <Xns94DEADC003D10raf256com@203.29.75.35>
tho### [at] trfde news:4095ecd3@news.povray.org

> No, it is valid in 3.6 and should give you tricubic interpolation.

Oh, I didnt know that.

But - resuts of this interpolation are far worse then even without any 
interpolation (see b-t.binaries), it produces some cell-like effect,m with 
gives even more pixelized image then oryginal.

-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics


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