Re: [rp-ml] STL files

From: Adrian Bowyer <A.Bowyer_at_bath.ac.uk>
Date: Wed Dec 06 2006 - 15:22:30 EET

Delft Spline Systems wrote:

> I would say that
> refusing to build is a problem of the RP software, not of the STL data
> format.

Not really. This is a GIGO effect. If a solid object being described by its
surface has a gap in that surface (for example) then it either has zero volume,
or it occupies the entire Universe. (Or rather the whole of Euclidean Space,
which is bigger, even if it is a fiction...) Of course software can sometimes
patch this up, but for any given patch-up algorithm it is inevitable that -
sooner or later - that "sometimes" will fail.

This was a problem with a known simple solution when the STL format was defined.
  As that solution had been around since the time of Poincaré (1854 - 1912), if
not Euler (1707 - 1783), that is a bit annoying. It's the sort of thing that
happens when you let mechanical engineers (like me) define a data structure...

Yours

Adrian

http://staff.bath.ac.uk/ensab
http://reprap.org
Received on Wed Dec 06 14:11:34 2006

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