Quick answer: csPolygonMeshTools is indeed deprecated (and clearly
marked that way as well in the api docs). csTriangleMeshTools is the
new one.

Greetings,

On 6/28/07, Scott Johnson <[EMAIL PROTECTED]> wrote:
> Hi Everyone.
>
> Sorry, this is somewhat of a long email, but I wanted to poll the CS
> user community.
>
> I learned yesterday that the <p> tag inside the Crystal Space file
> format is going to be going away, and that <t> (triangles) are soon
> going to be the only way to place polygons into a CS file.  This isn't a
> big problem, but it did send me for somewhat of a loop with the COLLADA
> conversion stuff.  The problem I'm encountering is that there is a
> general <p> tag inside COLLADA.  Thus, any polygons using this tag would
> need to be triangulated before converting to CS format.  Again, this
> isn't a major problem- I'm well versed in the magic of Delaunay
> Triangulations ;).  The problem I'm having is deciding HOW I should
> attack this.  I have come up with probably three somewhat different
> solutions:
>
> 1. Create a separate interface, iTriangulator, and implement the
> triangulation method within this (either using an external LGPL-covered
> library, or implement my own).  The problem with this approach is the
> data structure.  Typically, Delaunay Triangulation algorithms are run on
> a data structure called a DCEL (Doubly-Connected Edge List), which is
> essentially a set of linked lists over the vertices and edges of a
> polygon.  Unfortunately, as I can tell, CS doesn't really implement this
> (unless I just didn't see it in my looking over the API) - at least not
> directly (it might be implemented inside some class somewhere, but not
> that I saw on looking over the API).  I could add this data structure as
> either an internal data structure to iTriangulator, or possibly as an
> external interface, iDCEL.  This might get too low-level, though, and
> possibly might not be useful to the general public.
>
> 2. Write an internal routine into the COLLADA convertor that utilizes a
> data structure, and then just converts for the sake of the COLLADA
> conversion library.  This is probably the quickest method, but my
> intuition tells me that a triangulation system, once written, might be
> useful to others.  Thus the reason I thought maybe I should separate it
> into another library, so others can use it.
>
> 3. Attempt to convert polygons to an existing internal CS data
> structure, such as csPolygonMeshTools, and then use the existing
> Triangulate() function on it.  This, at first glance, appears to be the
> best method, but when I last checked, it said something about being
> deprecated (which I can't seem to find now - I may have been half
> asleep), which makes me nervous.  I bring this up because I don't know
> enough about this interface to know whether or not it's going to go away
> in the near future (as I found out about <p> hehe - although in all
> consolation, it wouldn't have worked, anyway...so it was good to know.
> Thanks, res!)
>
> So, this leads us to my major question - which of these methods (or
> possibly a method I didn't list) would be the best approach?  Once I get
> started, I think I could probably implement this in a matter of 2-3
> days, so I don't anticipate that this will set my schedule back too
> terribly much.  One thing that concerns me, however, is the
> implementation.  I would rather use an existing implementation, since
> it's a known algorithm, and I've heard there are a lot of little demons
> to contend with when implementing DT.  Thus, it would probably be better
> in this case not to re-invent the wheel (although I am fond of doing
> that ;)  ).  In addition, I don't want to add a lot of bloat to the CS
> engine by creating additional data structures which already exist in
> another form.
>
> Thanks for any suggestions/comments/questions you can relate on this issue!
>
> ~Scott
>
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and CEL (http://cel.crystalspace3d.org)
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