At 08:44 PM 10/31/96 -0800, ZERVOS SPILIOS wrote
>A couple of questions on the STL format:
>1/ Are STL files from Pro/E different from STL files from I-DEAS, for example?
>In other words, does each CAD sw export proprietary STL files? Or is it that if
>one plays around with the STL parameters, eg chord length & angle control for
>Pro/E, will end up with the same STL after all?
>2/ Is there any web-site or publication with details on the way STL files are
>structured?
Different programs will generate different sets of triangles, since the is no
"right" way to do the tessellation.
The file requirements are the same however.
The stl format is specified in a 3D Systems document. But it is very simple
and can be described briefly as:
80 byte header; (could be anything...)
4 byte triangle count;
then 50 bytes per triangle consisting of
12 bytes 3 float Triangle normal pointing out of material (redundant)
12 bytes 3 float Point 1 (x,y,z)
12 bytes 3 float point 2 (x,y,z)
12 bytes 3 float Point 3 (x,y,z)
2 bytes binary zeros (usualy...)
The floats are binary IEEE little endian (intel) format.
The triangle count is binary little endian (intel) format.
Other requirements:
The points are ordered counter-clockwise when viewed from the outside.
Every edge of every trangle matches Exactly with another edge (in pairs).
C. Brock Rooney, Pres., Brock Rooney & Associates Inc. (Brockware)
268 George St. Birmingham Michigan 48009 USA
(810) 645-0236 fax/bbs (810) 645-9020 email brock@mich.com
This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:37:41 EEST