I don't know what I'm doing wrong with this scene. I created an isosurface
(the same you can see in the previous animation I posted) and differenced
half of it from a plane.  When observed from sideways the result looks fine,
but as I rotated it, a large white area appeared. Well, an animation with 60
frames is woth 60000 words, so go ahead and take a look.

If someone knows what I am doing wrong, please tell me. Oh, and if it is too
obvious, feel free to nag me from here to Kabul.

Here is the scene. It uses Ingo Janssen's "param.inc":

light_source { <0, 100, 00> color rgb 1.0 }
light_source { <0, 10, -100> color rgb 1.0 }

camera {
  location  <0.0 , .10 , -10.0>
  look_at   <0.0 , 0.0 , 0.0>
  angle 15
}

background { rgb 2 }

#declare Fx = function(u, v) {sin(u)*sin(v) +sin(20*v)*0.05}
#declare Fy = function(u, v) {cos(u)*cos(v) +cos(20*u)*0.05}
#declare Fz = function(u, v) {sin(v)}

#declare Umin = -1*pi;
#declare Umax =  1*pi;
#declare Vmin = -1*pi;
#declare Vmax =  1*pi;

#declare Iter_U = 100;
#declare Iter_V = 100;

#declare WriteReadMesh = "Parafun.msh"

#include "param.inc"
Parametric()

#declare Parafun = difference {
  object {
    Surface
    rotate y*90
    rotate x*90
    texture {
      pigment { color rgb z }
      finish { specular 1 }
    }
  }
  plane { x 0 }
  rotate z*-90
  translate y/2
}

object {
  Parafun
  texture {
    pigment { color rgb z }
    finish { specular 1 }
  }
  rotate x*360*.clock
}

Any help will be greatly apreciated.

Thanks,

Ruy

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Attachments:
Download 'Parafun.mpg' (543 KB)

Don't know for parmetrics but perhaps you have to add max_trace or
all_intersection, as with isosurfaces. Without this, pov will only calculate
the first found intersection, which is cut of by the CSG.

Marc-Hendrik

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"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> escreveu na mensagem
news:3bbeefae$1@news.povray.org...
> Don't know for parmetrics but perhaps you have to add max_trace or
> all_intersection, as with isosurfaces. Without this, pov will only
calculate
> the first found intersection, which is cut of by the CSG.
>
> Marc-Hendrik

Actually the isosurface is first transformed into a mesh2 object by Ingo's
include file. Only then it is differenced from the plane. Do max_trace and
all_intersection interfere with meshes at all?

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Ruy schrieb in Nachricht <3bbef522@news.povray.org>...
>"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> escreveu na
mensagem
>news:3bbeefae$1@news.povray.org...
>> Don't know for parmetrics but perhaps you have to add max_trace or
>> all_intersection, as with isosurfaces. Without this, pov will only
>calculate
>> the first found intersection, which is cut of by the CSG.
>>
>> Marc-Hendrik
>
>Actually the isosurface is first transformed into a mesh2 object by Ingo's
>include file. Only then it is differenced from the plane. Do max_trace and
>all_intersection interfere with meshes at all?
>

No. Has to be something else.

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Oh wait! You make a CSG with a mesh? That won't work. MegaPov  had Solid
triangle meshes where you could specify an inside-vector, but that seems not
to exist in v3.5 anymore. Without you can't difference or intersect a mesh.
Or did that change?

Marc-Hendrik

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Wasn't it Ruy who wrote:
>I don't know what I'm doing wrong with this scene. I created an isosurface
>(the same you can see in the previous animation I posted) and differenced
>half of it from a plane.  When observed from sideways the result looks fine,
>but as I rotated it, a large white area appeared. Well, an animation with 60
>frames is woth 60000 words, so go ahead and take a look.
>
>If someone knows what I am doing wrong, please tell me. Oh, and if it is too
>obvious, feel free to nag me from here to Kabul.
>
>Here is the scene. It uses Ingo Janssen's "param.inc":

When you use Ingo's "param.inc" file, it converts your functions into a
*mesh2* object rather than an actual isosurface. Mesh2 objects can't be
used in differences.

The docs say:

   There are six totally thin, finite objects which have no well-defined 
   inside. They are bicubic patch, disc, smooth triangle, triangle, 
   polygon and mesh / mesh2. They may be combined in CSG union but 
   cannot be used in other types of CSG (or inside a clipped_by 
   statement).

-- 
Mike Williams
Gentleman of Leisure

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> When you use Ingo's "param.inc" file, it converts your functions into a
> *mesh2* object rather than an actual isosurface. Mesh2 objects can't be
> used in differences.
>
> The docs say:
>
>    There are six totally thin, finite objects which have no well-defined
>    inside. They are bicubic patch, disc, smooth triangle, triangle,
>    polygon and mesh / mesh2. They may be combined in CSG union but
>    cannot be used in other types of CSG (or inside a clipped_by
>    statement).
>
> --
> Mike Williams
> Gentleman of Leisure

Well, too bad. Anyway, parametric equations give us such amazing flexibility
that it didn't take 3 minutes before I got even better "sblorgles" just
playing with the parameters.

Thanks for the pointer.

Ruy

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Can anyone tell me where a copy of Ingo's "param.inc" can be found?  Thanks.

Cris Williams

"Mike Williams" <mik### [at] nospamplease> wrote in message
news:ot5### [at] econymdemoncouk...
> Wasn't it Ruy who wrote:
> >I don't know what I'm doing wrong with this scene. I created an
isosurface
> >(the same you can see in the previous animation I posted) and differenced
> >half of it from a plane.  When observed from sideways the result looks
fine,
> >but as I rotated it, a large white area appeared. Well, an animation with
60
> >frames is woth 60000 words, so go ahead and take a look.
> >
> >If someone knows what I am doing wrong, please tell me. Oh, and if it is
too
> >obvious, feel free to nag me from here to Kabul.
> >
> >Here is the scene. It uses Ingo Janssen's "param.inc":
>
> When you use Ingo's "param.inc" file, it converts your functions into a
> *mesh2* object rather than an actual isosurface. Mesh2 objects can't be
> used in differences.
>
> The docs say:
>
>    There are six totally thin, finite objects which have no well-defined
>    inside. They are bicubic patch, disc, smooth triangle, triangle,
>    polygon and mesh / mesh2. They may be combined in CSG union but
>    cannot be used in other types of CSG (or inside a clipped_by
>    statement).
>
> --
> Mike Williams
> Gentleman of Leisure

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Look in Povray.binaries.scene-files for "param.inc".

Marc-Hendrik

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