Okay basically I'm attempting to render a beer mug with beer in it.


Using wings3d I constructed the Mug model...

Using model of mug I created the fluid in the glass... ( I extracted only
the polygons on the INSIDE of the glass to do this...)  then... I exported
both meshs into .obj files

------

Using Poseray I rewound the triangles and normals on the the fluid for the
mug... this was needed -concidering how i obtained the fluid volume in the
first place from the mug triangles.

Using Poseray I converted both models to povray files...

-----
Using povray 3.6.1 I rendered the Mug & mug fluid...

RESULTS:

  -The Mug by itself is just great... transparent... nice... cool.

  -The Fluid by itself... just as nice.

  -When the fluid is in the mug, you can see the fluid color ONLY if veiwed
from birds eye into glass.

  If I enlarge the volume of the fluid to be slightly larger than the
interior volume of the mug ( but still inside the glass of the mug ) then I
can see the color of the fluid...  BUT this is obviously flawed.

------------

  So my question is what have i done wrong?  ;)

  other notes:

     glass is "hollow"
     have tried hollow and not hollow fluid...

     As long as the mesh for the fluid is up against the mesh for the glass
then I can see no color... but this is the accurate physical
representation....
ERRRRRR
  Anyone else ever try this...

  I will post some code if asked but note my data files for geometry are to
large to post... I would have to generate something smaller.

TIA lordcontrary

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lordcontrary nous apporta ses lumieres en ce 2005-06-03 14:31:
> Okay basically I'm attempting to render a beer mug with beer in it.
> 
> 
> Using wings3d I constructed the Mug model...
> 
> Using model of mug I created the fluid in the glass... ( I extracted only
> the polygons on the INSIDE of the glass to do this...)  then... I exported
> both meshs into .obj files
> 
> ------
> 
> Using Poseray I rewound the triangles and normals on the the fluid for the
> mug... this was needed -concidering how i obtained the fluid volume in the
> first place from the mug triangles.
> 
> Using Poseray I converted both models to povray files...
> 
> -----
> Using povray 3.6.1 I rendered the Mug & mug fluid...
> 
> RESULTS:
> 
>   -The Mug by itself is just great... transparent... nice... cool.
> 
>   -The Fluid by itself... just as nice.
> 
>   -When the fluid is in the mug, you can see the fluid color ONLY if veiwed
> from birds eye into glass.
> 
>   If I enlarge the volume of the fluid to be slightly larger than the
> interior volume of the mug ( but still inside the glass of the mug ) then I
> can see the color of the fluid...  BUT this is obviously flawed.
> 
> ------------
> 
>   So my question is what have i done wrong?  ;)
> 
>   other notes:
> 
>      glass is "hollow"
>      have tried hollow and not hollow fluid...
> 
>      As long as the mesh for the fluid is up against the mesh for the glass
> then I can see no color... but this is the accurate physical
> representation....
> ERRRRRR
>   Anyone else ever try this...
> 
>   I will post some code if asked but note my data files for geometry are to
> large to post... I would have to generate something smaller.
> 
> TIA lordcontrary
> 
You are experiencing the soincident surfaces problem. When 2 surfaces meet exactly,
you can't tell 
whitch one you meet first.
You alreadi tried using a larger iner shape, try a smaler scale increase as your
increase may have 
been to large.
Try scaling down by a very small value.
As you are using meshes, try rotating the incide object. Something like rotate 0.1*y
can be enough.
If you post your source, try ZIPing it with maximum compression, it should compress
well as the data 
set is quite limited: 0..9+"."+","+"<"+">"+"-"+some letters and the space.

Alain

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lordcontrary <lor### [at] yahoocom> wrote:
>      glass is "hollow"

  Why? All the glasses I have seen have been very solid.

>      have tried hollow and not hollow fluid...

  Why? Are you using media?

-- 
                                                          - Warp

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Warp <war### [at] tagpovrayorg> wrote:
> lordcontrary <lor### [at] yahoocom> wrote:
> >      glass is "hollow"
>
>   Why? All the glasses I have seen have been very solid.
>
> >      have tried hollow and not hollow fluid...
>
>   Why? Are you using media?
>
> --
>                                                           - Warp

I actually was fooling with many things at once... have not used povray in
oh... 8 years... refreshing my memory on new concepts...  media was one of
them... and I thought it applied in this context?  yep... media was used and
a bunch of other goodies.   anywho...

I did scale back the volume and now I have "beer" in my mug.  Thanks.

I did have one problem that needed to be fixed as well... before the effect
was perfect...

When I made the "fluid" I did not have wings3d tesselate the geometry...
This was done during a convertion ( possibly .obj ->.pov )...  turns out
the convertion program did a terrible job of it.  When i converted the data
back I learned it tesselated it in a terrible fashion.  ( not a rant - in
the end I actually manually tesselated some geometry one triangle at a time
to get it right )

Now tesselation by itself is not a problem but when it created vertex
normals they were not consistent at the edges... it made all the refraction
a trainwreck.  Lesson learned... rely on convertion programs ONLY to
convert... not to make adjustments to your geometry...

..... thanks for the feedback... off to make a neon bar light to go with my
drink!

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lordcontrary <lor### [at] yahoocom> wrote:
> I actually was fooling with many things at once... have not used povray in
> oh... 8 years... refreshing my memory on new concepts...  media was one of
> them... and I thought it applied in this context?  yep... media was used and
> a bunch of other goodies.   anywho...

  I just got the impression that you had a confusion about what 'hollow'
does in POV-Ray. That keyword is exclusively related to media (and fog)
and nothing else. If you don't have any media/fog in your scene and
you are getting something weird, 'hollow' will not fix it nor have any
effect whatsoever so it's pretty useless to try it. :)

-- 
                                                          - Warp

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