#define DTK_IN 1 // Internal use
#define DTK_ACIS 2 // Acis files .sat or .sab
#define DTK_STEP 4 // Step files .stp .step
#define DTK_PARASOLID 5 // Parasolid files .x_t .x_b .xmt
#define DTK_IGES 6 // Iges files .igs .iges
#define DTK_CADDS 7 // Cadds files _pd
#define DTK_CATIAV4 8 // Catia V4 files
#define DTK_CATIAV5 9 // Catia V5 files
#define DTK_PROE 12 // ProEngineer - Creo files
#define DTK_ROBFACE 13 // Robface files
#define DTK_ROBFACE_FACET 14 // Robface facetted files
#define DTK_SOLIDWORKS 15 // Solidworks files
#define DTK_SOLIDEDGE 16 // Solidedge files
#define DTK_UNIGRAPHICS 17 // Unigraphics NX files
#define DTK_VDAFS 18 // Vda files
#define DTK_UNISURF 20 // Unisurf files
#define DTK_JT 21 // Jt files
#define DTK_STL 22 // Stl files
#define DTK_VRML 23 // Vrml files
#define DTK_INVENTOR 25 // Inventor files
#define DTK_CGR 26 // Cgr files
#define DTK_3DXML 28 // 3DXml files
#define DTK_CEREC 29 // Cerec files
#define DTK_DCM 30 // Dcm files
#define DTK_PROCERA 31 // Procera files
#define DTK_CERCON 32 // Cercon files
#define DTK_DXF 33 // Dxf 2D Files
#define DTK_CATIAV6 34 // Catia V6 files
#define DTK_DWG 35 // Dwg files
#define DTK_PLMXML 36 // PLM Xml files
#define DTK_COLLADA 37 // Collada files
#define DTK_U3D 38 // U3D files
#define DTK_PDF 39 // Pdf 3D files
#define DTK_RNXML 41 // RnXml files
#define DTK_OCC 42 // Open Cascade files
#define DTK_BREPOCC 42 // Open Cascade Brep files
#define DTK_PDF2D 43 // Pdf Drawing files
#define DTK_3DM 44 // Rhinoceros 3D files
#define DTK_OBJ 45 // Rhinoceros 3D files
#define DTK_PARASOLIDB 46 // Parasolid files .x_b
#define DTK_PRC 47 // PRC files
#define DTK_IFC 48 // IFC files
#define DTK_EMF 49 // EMF files
#define DTK_3MF 50 // 3MF files
#define DTK_RVT 52 // Revit files
#define DTK_CRV 53 // CreoView files
#define DTK_GLTF 54 // Gltf files
#define DTK_FBX 55 // Fbx files
#define DTK_SMG 58 // Smg files
#define DTK_F3D 59 // F3d files
#define DTK_DSTV 60 // Dstv files
#define DTK_CGM 61 // Cgm files
#define DTK_NAVIS 62 // Navis files
#define DTK_DXF3D 63 // DXF 3D files
#define DTK_QIF 65 // Qif files
#define DTK_ZW3D 66 // Zw3d files
