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["Pablo Carneiro Elias" <>]

Ok, sorry about the missing dll. You've helped my alot! ;] Thanks! I'll not take more of you time.. well, I think there was really some kind of problem with my mesh as you've said..., I've exported it from max and some how It was built with independet triangles, so, nothing can be done with it.. I've arealy fixed it and I can solve the problem now! Thank you again for you patient and helpfulness..


[]'s Pablo

2007/12/3, Fernando Cacciola <>:

Hi Pablo,

> I'm trying some other solution here, I suspect that this model is already
> simple enough and no triangle can be removed somehow without changing the
> shape....
>
Right, that's exactly the case here.
I tested it and every edge in your example is "non-collapsable".

One way to notice this is via a visitor, as shown in the second example in the
user manual.

In fact, if you use that example you can see how it reports that none of the
191316 edges can be collapsed due to topological constriants.
Furthermore, if you use the LindstromTurk policies with that example, you can
see that more than 190000 edges cannot be collapsed due to cost computation
constrians, which in this case means that any new vertex placement would incurr
a very large error, so it discarded.

> I need some topological structure where I can query for adjacent triangles
> of a vertice / triangle or adjecent edges of a vertive / egde.. is there
> anything like this in cgal.. (I think there is)..
> any one can give-me an
> example or a doc about some structure like this? I'm currently using a CGAL
> Polyhedron to store my triangles...

You can query all adjacencies of a given element using the Polyhedron, but when
you build a polyhedron you do the opposite: define those adjacencies rather than
query them.
I did not investigate why none of the edges are non-collapsable, but from your
question above: is this a real mesh or just a collection of isolated triangles?
that is, are edges shared between triangles? If not, then you probem is how to
build a proper mesh from the whatever input you have.
If that's the case, please top-post a question, with a proper subject, asking
for that specifically, providing details of the input you have and what you know
about the adjacencies of the triangles (if anything)

Btw: I couldn't use your viewer because it depends on a "osgViewer.dll" which I
don't have.

HTH

Fernando Cacciola
GeometryFactory
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