The 3D printing consultant was fine with our 3D DXF until he got to the grade mesh. He requested that we send him an STL file, which we did not know what was. It is a 3D Stereolithography file and it's common in 3D apps. Archicad doesn't support it for export. We tracked down an open-source app called MeshLab which saves STL. It does not, however, open DXF. It does open 3DS. So we saved as 3DS from Archicad, opened that in MeshLab, saved as STL, done. From illiteracy to FTP upload complete in about three minutes. MeshLab is free and runs on OS X, Linux, and Windows.
