“.stl” files are typically created in your CAD system, but can be created in other software packages also. As a general rule, your product design can be exported or “saved as” to the .stl file format from your CAD software. Stl files are made up of tessellated triangles placed on the solid model surface. Therefore, on curved geometries, smaller triangles will achieve better surface resolution. Large triangles will result in a polygonized or facetted surface. What you see as triangular facets on your .stl viewing software will be replicated on your pattern.
Methods vary with different CAD systems but the criteria should be a balance between acceptable surface resolution and the size of the data file. Large radii and long, gently curved surfaces show individual triangles the most. Examine these areas for acceptability before preparing to build parts.
|A wireframe view of a tessellated.stl file|