These are quotes of other posting I have saved:"<<<<
:My first comment is “STL is not a graphics file,” it’s a 3D data format.
My second comment is “STL is intended to be an output file, not an input file <<<<<
What is an STL file? It’s basically a file which “slices” a 3D model into a series of very thin 2D “layers.” This output is then used to drive a stereolithography (or similar) machine which produces physical prototypes through layer-by-layer deposition
This file format is not a CAD format, nor is it a graphics format… it is merely the final step before making that physical part.
Each layer consists of a series of line segments, each of which consists of two end vertices. I >>>>” That means it uses triangles!!
If you have used the stl su plugin before you probably noted it use to show info on the number of trias deleted. I think that has now been deleted with latest release. That was in a recent post plugin in author should have better info.If you use a stl file to repeatedly create a SU model you will find some problems. The bottom line is the stl format does not carry topographical info but approixates with trias:slight_smile:
If you us SU to make a clean model and export to support print that is ok.
Here is a comment on obj .>>> Spline meshes
Converting an .obj mesh file to a smooth T-spline surface is a popular feature in the T-Splines for Rhino plugin because T-spline surfaces are NURBS compatible and can be passed downstream to other applications as a watertight poly-surface. STL files are not recommended for conversion because the model is very high density of triangles and one runs low on memory.>>>>
STL to Su Issues