StereoLithography STL Exporter

This export converter writes out the 3d database to an ASCII formatted or binary formatted 'StereoLithography STL' file which can be read by many CAD/CAM related software packages.

An object called 'test' containing a single triangle is written to the STL file as follows:

solid test
  facet normal 0 1 0
    outer loop
      vertex 0 4 0
      vertex 0.517638 3.93185 0
      vertex 0.5 3.93185 -0.133975
    endloop
  endfacet
endsolid test

Dialog Box Options

The following information explains the various options on the dialog box:

Output Only 1 'Solid' Entity

If this option is enabled (checkmarked) then each object defined within the database will be output as a separate object in the STL file (enclosed within its own 'solid' definition). If this option is disabled then all objects within the database will be compressed into a single entity before being output to the STL file as a single 'solid' definition.

Binary Output

If this option is enabled (checkmarked) then the STL file will be written in binary, else it will be written in ASCII format.

NOTE: the binary file format does not allow more than one 'solid' to be defined so this export converter compresses all of the objects defined within the 3d database into a single object before outputting them to the binary STL file (this is equivalent to enabling the 'Output Only 1 Solid Entity' option. This does not apply for the ASCI I mode which allows one or more 'solid' definitions to be created.

Reverse Orientation of Triangles

If this option is enabled (checkmarked) then the orientation of all triangles will be reversed (this will effectively swap the orientation of the triangles' geometric normals). This option will not flip the orientation of the vertex normals.

Flip Geometric Normals

If this option is enabled (checkmarked) then the orientation of each geometric normal will be reversed. You may need to enable this option if the STL file looks 'dark' in the final destination rendering program.

Line Terminator Type

This common option selects which line terminator is to be used for the ASCII output file:

• Files destined for DOS/PC machines should use CR/LF,
• Files for UNIX machines should use LF, and
• Files for Macintosh machines should use CR.

The default is specific to which machine this converter is presently running on: CRLF for DOS/PC, LF for UNIX and CR for Macintosh. This option normally does not have to be specified unless you will be using the exported ASCII file on a different type of computer.