Jon Buller nous apporta ses lumieres en ce 15/05/2006 19:03:
> I've been trying to make a rather blatent rip-off of an image on
> http://www.sover.net/~tlongtin/, but as you can see in the attached image,
> I'm having a small problem.  (OK, it's not an exact rip-off, the holes on
> mine are more evenly spaced, and I have a class in differential geometry 20
> years ago to thank for that.  OTOH, the textures on the original are not so
> good, and mine are much, much worse.  Perhaps with a huge pile of greebles
> added on... 8^)
> 
> I have (or at least should have) a properly enclosed mesh object, along with
> an inside vector for it.  It's the green object in the image, if you haven't
> guessed. 8^)  It's a mesh with some cylinders differenced out to make the
> holes for the torus to go through.  I think it would be a huge pain to try
> to compute the holes as part of the mesh, but it could be just because I
> haven't thought about it enough.
> 
> The POVray help files say that this should be OK for CSG, but I get a parse
> warning saying "Patch objects not allowed in intersection" at the closing
> brace for my difference object.  And if you look carefully at the holes,
> they don't have any depth like the edge of the band does.  (Or the holes in
> the torus, which is the same thickness as the band.)
> 
> Also, the documentation talks about the vector as the location of a point
> inside the mesh, but then talks about it as if it is some nebulous
> direction for POV-Ray to shoot from random points to determine
> "insidedness".  This is not the most clear exposition of the situation, and
> could use some polish IMHO.  If someone will explain the exact algorithms
> involved, I'll make a stab at cleaning it up a bit.
> 
> BTW, I am using POV-Ray version 3.6.1b.icl8.win32
> 
> Jon
> 
> 
> 
> ------------------------------------------------------------------------
> 
You can substract or intersect from a patch object, but you can't substract/intersect
a patch object 
from another object. The patch object is only a surface, even if it have a defined
interior.

-- 
Alain
-------------------------------------------------
Unitarianism: Come let us reason together about this shit.

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