-Hail

   Here is a piece of code that produce some weird results, change the
lambda and scale to see how it affects the texture. I think I have seen this
in older POV vresions. Look in the binaries for the image.

#declare Black_mirror =
   texture {
      pigment {color rgb 0}
      finish {
         specular .8 roughness 0.005
         reflection {0.2,0.8 falloff 1}
      }
   }
background {rgb 1}
#declare Povray_Logo =
merge {
   difference {
      cone {2*y, 1, -4.002*y, 0 }
      sphere {2*y, 1.4 scale <1,1,2>}
    texture {Black_mirror}
   }
   difference {
      sphere {0, 1 scale <2.6, 2.2, 1>}
      sphere {0, 1 scale <2.3, 1.8, 2> translate <-0.35, 0, 0>}
      rotate z*30 translate 2*y
    texture { pigment_pattern { bozo color_map {[0 rgb 0][1 rgb 1]} scale .3
turbulence .17 lambda 8.4 octaves 12 omega .9}
    texture_map {[0.0 Black_mirror]
    [1.0 finish {specular .7 roughness 1/125 metallic .35 reflection
{0.2,0.4 falloff 2.05}}]}}
   }
   rotate <0, clock*360, -25>
   translate <-0.5,-0.35,0>
   scale 1/4
}
   sphere {2*y, 1
   finish {specular .75 roughness 1/14 metallic .35 reflection {0.2,0.8
falloff 1.5 metallic .05}}
   pigment {red .28}
   rotate <0, 0, -25>
   translate <-0.5,-0.35,0>
   scale 1/4
}
camera {
 location <0,0.01,-2.075>
 look_at 0
}
light_source {
 <3,5,-4> rgb 1
}
object {Povray_Logo}

P2-450, 64Mb Ram W2k

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Forgot to say that I was using Pov 3.5 b-4

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Vampyrium <cyb### [at] hotmailcom> wrote:
:    Here is a piece of code that produce some weird results, change the
: lambda and scale to see how it affects the texture.

  I think that bug reports would be nicer if at least *some* textual
description of the problem was provided. "This produces weird results" is
certainly not descriptive enough. Also an opinion/knowledge on how it should
work instead of the current behaviour would be good. This way developers don't
have to guess what are you talking about.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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I generically agree with you, but did you check his image?
For me it seems the problem is visible on the top right of
the POV logo.

-- 
Adrien Beau - adr### [at] freefr - http://adrien.beau.free.fr
 Mes propos n'engagent que moi et en aucun cas mes employeurs

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On Fri, 28 Sep 2001 13:54:52 +0200, Adrien Beau wrote:
>I generically agree with you, but did you check his image?

The point is, sometimes it's easier to fix a problem from a textual 
description of the problem than to extract the source, render it, and then
smack your forehead and say "well, of course, the veeblefetzer is 
discombobulated.  I should have seen that coming."  That's not to say 
the source isn't useful as a test case, but sometimes I, for example,
am not at a machine on which I can actually render things and look at
the results but I can browse the source code and look for something that
would cause the described results.

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbt 1}hollow interior{media{emission T}}finish{
reflection.1}}#end Z(-x-x.2y)Z(-x-x.4x)camera{location z*-10rotate x*90}

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> smack your forehead and say "well, of course, the veeblefetzer is
> discombobulated.  I should have seen that coming."  That's not to say

Well then hurry up and recombobulate that darn veeblefetzer, people are
waiting :)

-tgq


--
camera{location z*13look_at 0}light_source{15 15looks_like{sphere{0 10
}pigment{rgb 1}finish{ambient 15}}}union{torus{3,0.5rotate x*90}cone{y
*4,.5,-y*8,0}cone{-x*4,.5,x*8,0}pigment{rgb<.7,.6,.4>}finish{ambient 0
diffuse 0reflection{1fresnel on metallic 1}}interior{ior 25}rotate 15}
plane{y,-7pigment{checker rgb 0rgb 1scale 4}finish{diffuse.1}}//   TGQ

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I agree with you all along. It's just that

Warp wrote:
> 
> "This produces weird results" is
> certainly not descriptive enough.

made me wonder if he had seen the picture. The rest of his
comments, and yours, still apply.

-- 
Adrien Beau - adr### [at] freefr - http://adrien.beau.free.fr
 Mes propos n'engagent que moi et en aucun cas mes employeurs

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I made some tests and I don't think scaling the turbulence is the problem.

The following code does not show the inconsistency in the texture, but if
you uncomment the "octaves 12" , you can see it again - at all sides of the
sphere. As long as octaves is less than 10, nothing happens. The "break"
seems to be at the box{-10,10}.

Hope that helps,

Marc-Hendrik

// ------------- code -----------
background {rgb 1}

sphere {0, 14

    texture

       bozo  turbulence .17 lambda 8.4 // octaves 12 //omega .9
       texture_map {
              [0.0 pigment {color rgb <0,1,0>} ]
              [1.0 pigment {color rgb <1,0,0>} ]
       }

    }
}

camera {
location <0,0.01,-16.075*(10/3)>
look_at 0
}
light_source {
<3,5,-4>*4 rgb 1
}

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I just noticed, from the docs regarding octaves (6.7.12.6.4.1  Octaves):

Legal values range from 1 to 10.


>     texture { pigment_pattern { bozo color_map {[0 rgb 0][1 rgb 1]} scale
.3
> turbulence .17 lambda 8.4 octaves 12 omega .9}


Octaves 12 is not supposed to be legal.

-tgq

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Oh, that's probably why the problems disappears with octaves less then 10 (I
tried at least with octaves 9.99). BUT with octaves 10 you have the problem
still there. Suggestion: change the Docs :-)

Marc-Hendrik


Trevor Quayle schrieb in Nachricht <3bb4accf$1@news.povray.org>...
>I just noticed, from the docs regarding octaves (6.7.12.6.4.1  Octaves):
>
>Legal values range from 1 to 10.
>
>
>>     texture { pigment_pattern { bozo color_map {[0 rgb 0][1 rgb 1]} scale
>.3
>> turbulence .17 lambda 8.4 octaves 12 omega .9}
>
>
>Octaves 12 is not supposed to be legal.
>
>-tgq
>
>

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