Hello there,

Is it a bug or (most probable) did I miss something ?

I have this very nice image of a checker (this is just for the sake of the
example and not the image I am actually using) stored in a file called
test.pgm:
content of test.pgm:
P2
2 2
255
0 100
100 0

I am using this image in a pigment function, or whatever you might want to
call that:
#local fn_pig= function {
  pigment {
    image_map {
      pgm "test.pgm"
      map_type 0
      interpolate 0
      once
    }
  }
}
#local fn_pig_Height=function { (fn_pig(x, y, 0).red ) }

Then, I just call this function many times, using a loop:
#declare Pas = 0.1;
#declare Loc_x = 0;
#while (Loc_x < 1)
  #declare Loc_y = 0;
  #while (Loc_y < 1)
    #debug concat("x=",str(Loc_x,3,3)," y=",str(Loc_y,3,3)," fn_pig_Height =
",str(fn_pig_Height(Loc_x,Loc_y,0),5,5),"n")
    #declare Loc_y = Loc_y + Pas;
  #end
  #debug "n"
  #declare Loc_x = Loc_x + Pas;
#end

and HERE IS MY QUESTION !!! For each x value strictly lower than 1, and for
each y value stricly lower than 1 (x<1 and y<1), I get what I expect (0 or
0.39216, which is 100/255, depending on x and y). But, for x=1 and
y=anything, or for y=1 and x=anything, I get the value 1 !!
When I render this as an isosurface, I get a kind of wall around my
checker...
Could anyone help me out ?

Hope my description is clear. If not, please ask for more information...

S.

Post a reply to this message

Well , i have try to uderstand .was difficult ..

Well if i understand well ..

when you got one of x,y upper than one you got a 1 ... (insteed of 0??)

well i thing that commes from your once term in your pigment function ..

when x is upper than one then you are 'ouside' your image map than that take
the value one (probably due to outside of the imagemap is white (1) ))

same for y upper than one ..



..


did that help you ?

























news:web.44a3c005a26efc189e4a59f60@news.povray.org...
> Hello there,
>
> Is it a bug or (most probable) did I miss something ?
>
> I have this very nice image of a checker (this is just for the sake of the
> example and not the image I am actually using) stored in a file called
> test.pgm:
> content of test.pgm:
> P2
> 2 2
> 255
> 0 100
> 100 0
>
> I am using this image in a pigment function, or whatever you might want to
> call that:
> #local fn_pig= function {
>   pigment {
>     image_map {
>       pgm "test.pgm"
>       map_type 0
>       interpolate 0
>       once
>     }
>   }
> }
> #local fn_pig_Height=function { (fn_pig(x, y, 0).red ) }
>
> Then, I just call this function many times, using a loop:
> #declare Pas = 0.1;
> #declare Loc_x = 0;
> #while (Loc_x < 1)
>   #declare Loc_y = 0;
>   #while (Loc_y < 1)
>     #debug concat("x=",str(Loc_x,3,3)," y=",str(Loc_y,3,3)," fn_pig_Height
=
> ",str(fn_pig_Height(Loc_x,Loc_y,0),5,5),"n")
>     #declare Loc_y = Loc_y + Pas;
>   #end
>   #debug "n"
>   #declare Loc_x = Loc_x + Pas;
> #end
>
> and HERE IS MY QUESTION !!! For each x value strictly lower than 1, and
for
> each y value stricly lower than 1 (x<1 and y<1), I get what I expect (0 or
> 0.39216, which is 100/255, depending on x and y). But, for x=1 and
> y=anything, or for y=1 and x=anything, I get the value 1 !!
> When I render this as an isosurface, I get a kind of wall around my
> checker...
> Could anyone help me out ?
>
> Hope my description is clear. If not, please ask for more information...
>
> S.
>
>

Post a reply to this message

Sylvain wrote:
> Hello there,
> 

This is not the appropriate group for such questions.

Christoph

-- 
POV-Ray tutorials, include files, Landscape of the week:
http://www.imagico.de/ (Last updated 01 Jun. 2006)
MegaPOV with mechanics simulation: http://megapov.inetart.net/

Post a reply to this message

Sylvain wrote:
> Hello there,
> 
> Is it a bug or (most probable) did I miss something ?
> 
> I have this very nice image of a checker (this is just for the sake of the
> example and not the image I am actually using) stored in a file called

This is the wrong group for this question.  This group is for discussion of
the POV-Ray source code, not general questions of using POV-Ray.  Questions
about using POV-Ray should be asked/made in either povray.general or
povray.newusers.

	Thorsten, POV-Team

Post a reply to this message

Thorsten Froehlich <tho### [at] trfde> wrote:
> Sylvain wrote:
> > Hello there,
> >
> > Is it a bug or (most probable) did I miss something ?
> >
> > I have this very nice image of a checker (this is just for the sake of the
> > example and not the image I am actually using) stored in a file called
>
> This is the wrong group for this question.  This group is for discussion of
> the POV-Ray source code, not general questions of using POV-Ray.  Questions
> about using POV-Ray should be asked/made in either povray.general or
> povray.newusers.
>
>  Thorsten, POV-Team

Sorry about the mistake...

Post a reply to this message

Thorsten Froehlich wrote:
> This is the wrong group for this question.

   Perhaps this group could just be deleted? The vast majority of
posts are off-topic, and the few truely on-topic posts could have
perfectly been posted in eg. p.advanced-users.

Post a reply to this message

in fact i this this group dont have an appropriate understandable title
..cause programming can be ambiguous if you consider that building a scene
is programming it ..(as new users) ..


povray.source.programming will be less ambiguous ...

Well still off topic ....



news:44a40a88$1@news.povray.org...
> Thorsten Froehlich wrote:
> > This is the wrong group for this question.
>
>    Perhaps this group could just be deleted? The vast majority of
> posts are off-topic, and the few truely on-topic posts could have
> perfectly been posted in eg. p.advanced-users.

Post a reply to this message

NEWS wrote:
> in fact i this this group dont have an appropriate understandable title
> ..cause programming can be ambiguous if you consider that building a scene
> is programming it ..(as new users) ..

   It has been known for many years that this group *can't* have
an unambiguous title. There have been probably a couple of dozen
suggestions, all of which have been ambiguous or very unclear.

   Given that the amount of on-topic posts in this group is really
really small and the amount of off-topic posts is very high, I vote
for removal. This group doesn't serve its purpose (and the few posts
which are on-topic could be handled in another group).

Post a reply to this message