I figure that CGAL splits the mesh every N vertices or so so that it doesnt
have loops with 2000 things to go through, and then it doesnt make
theoretically one-mesh CSG results? If so, i don't know why it would use so
much memory??!? I saved an STL and viewed it in Sketchup and found that it
was made of sub meshes.

Please say the construction of the STL files from cgal and is there a way to
join them into one set of mesh arrays? is it always one mesh array the STL
file?

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I don't think CGAL has any optimization for making such operations faster.
CGAL likes to store everything in one huge object, and, due to the nature of
their data structures, they tend to use a lot of memory, as well as CPU
time.

Not sure if that helped - your questions was a bit hard to understand.

-Marius

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Thanks, I can confirm that it seems to be written to one STL array. I was
processing some opescads indifferent programs and some programs devide the
mesh into subgroups at 65534 vertices, for example i had a scad in sketchup
that was in one group devided into 5-7 sketchup components, so i was curious
if the original STL files were some kind of composite array mesh file. i.e.
x3d files i have been seeing recently have objects as multiple shapes in a
scene, and wavefront typs formats probably have just one mesh per file.

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