Re: Creating an .stl from unigraphics

Date: Tue Mar 09 1999 - 12:05:29 EET

     Dear Jeffrey,
     I have been using Unigraphics for STL files for 10 years. and this is
     what I have learned,
     The triangle tolerance setting will determine the cord height
     deviation that is allowed when triangulating the surface contour. This
     means that the smallest number you can set will yeild the smoothest
     part surface.
     English part values must range from .0001 to .1 inches
     The default is .003. (This will typically produce a poor part.)
     Metric part values must range from .0025 to 2.5 mm.
     The default is .08; (Once again, this will produce a poor part.)
     A triangulation tolerance value of about one-fourth the desired parts
     surface resolution is recommended. I would suggest that you try the
     minimum setting and see if the files get to big to process easily. It
     really depends on the complexity of file you are trying to make.
     I usually build parts with this set to no more than .0005in, / .010mm
     For high resolution: .0001in / .0025mm
     Unigraphics says that the adjacency tolerance is only needed when you
     are creating an STL from a surface model or a solid that includes
     surface model features. This controls what the software sees as a gap
     in the surface model.
     If you have used any surfaces in the costruction of the model, than
     set this to half the triangle tolerance listed above. Depending on
     which version of UG you are running, It may convert the solid to
     surfaces first, so I would just set this as a matter of course.
     You will often get degenerate triangles from high resolution UG -> STL
     files, but they can be cleaned up by the SLA software.
     Good Luck,
     Larry Blasch
     Systems Administrator for Engineering Services
     OPW Fueling Components
     P.O. Box 405003 Voice: (513) 870-3356
     Cincinnati, OH 45240-5003 USA Fax: (513) 870-3338
     * "Always remember you're unique, just like everyone else." *

______________________________ Reply Separator _________________________________
Subject: Creating an .stl from unigraphics
Author: ,"Narva, Jeffrey" <> at internet
Date: 3/8/99 4:03 PM

Can anyone tell me what the settings are for creating a .stl file from
unigraphics. preferred values for "tri tol" and "adjacency tol"? I was
just told what the options are and I have never dealt unigraphics before.
Any help is greatly appreciated.
Jeff Narva
Raytheon - Indianapolis
For more information about the rp-ml, see

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:51:11 EEST