Interface > Working with Data Exchange Formats > JT > About the Export Options in the JT Configuration File
  
About the Export Options in the JT Configuration File
You can create the jt.config configuration file and set a number of parameters in it to control the export of part and assembly models to the JT file format. You must select the Configure JT export with an external jtconfig file check box and set the relatedjt.config file name and path options in the export profile to specify the use of the jt.config file to configure the export of models to JT. When you specify to use the jt.config file for the export of models to JT, the options set in this file override the export options set in the JT export profile.
For example, you can set parameters in the jt.config file to control the export of the levels of detail (LODs) of the models to the JT format. You can export up to three levels of detail (LODs) to the JT format. An LOD is a graphical representation that consists of faceted surfaces. Each faceted surface is made up of a number of triangles. Many shaded triangles constitute the form and shape (tessellated) of an object. These shaded triangles represent the object. The more the triangles that describe the object, the more details you can view.
You can include the following parameters or export options in the jt.config file:
chordalOption—Specifies whether to apply the chordal value as an absolute value in model units or as a relative value that is a percentage of the part size.
structureOption—Specifies the mapping of the JT product structure to the JT file structure after export. The supported product structures are per_part, full_shatter, and monolithic.
writeWhichFiles—Specifies whether part or assembly data, or both part and assembly data are written to the JT files. You can set this parameter to the following values:
ALL—Specifies that part and assembly data are written to the JT files by default without filtering the contents.
PARTS_ONLY—Specifies that data that is exported as parts is written to the JT files.
ASSEMBLY_ONLY—Specifies that data that is exported as assembly structures is written to the JT files.
JtFileFormat—Specifies the JT file version for export. If set to the value of AUTO, the models are exported to JT version 9.5 which is the default version of the JT file format. Other values of this parameter are as follows:
80—JT file format version 8.0
81—JT file format version 8.1
82—JT file format version 8.2
90—JT file format version 9.0
91—JT file format version 9.1
92—JT file format version 9.2
93—JT file format version 9.3
94—JT file format version 9.4
95—JT file format version 9.5
100—JT file format version 10.0
101—JT file format version 10.1
102—JT file format version 10.2
includeBrep—Specifies the inclusion of the geometry brep definition in the JT files. You cannot include the xt_brep and the jt_brep data structures in the same file. You can use the autoXtBrep option with the includeBrep option to switch between jt_brep and xt_brep.
autoXtBrep—Specifies the automatic conversion of brep geometry to the Parasolid format during the export. If set to true, brep data is converted to the Parasolid format. If set to false, the brep data is stored in the proprietary JT format.
numLODs—Specifies the number of LOD definitions.
LOD—Specifies a grouping of parameters that controls tessellation.
Level—Specifies the current LOD number.
Chordal—Specifies the maximum distance that a tessellated line segment deviates from the actual curve it approximates. The value specified is as determined by the chordalOption option. If the chordal value exceeds model size, you can consider model size as the chordal value.
 
* For best results, use chordal values in conjunction with the Angular parameter. Chordal values affect the larger features of the model while the angular values affect the smaller features.
Length—Specifies the maximum absolute length of the tessellated line segments in a curve approximation. If the Length value exceeds model size, consider the default value (model_size/30).
Label—Specifies the user-defined name of an LOD.
Angular—Specifies the angle control value for the LOD definitions and the triangulation export to the JT format. This parameter limits the absolute maximum angle between two adjacent line segments in a curve approximation that lies in the range of 0 to 90.
You can set Angular as follows. The maximum angle value indicates coarse tessellation while the lowest value indicates fine tessellation and high quality LOD.
30 degrees for LOD 1
60 degrees for LOD 2
90 degrees for LOD 3
autoLODgeneration—Controls the automatic generation of the LODs.
autoLODuseStepSize—Controls the proportional use of the StepSize parameter during the automatic generation of the LODs.
LOD1angle …LOD2angle…LOD3angle—Regulates the additional improvement along curves with small radii for LOD 1, LOD 2, and LOD 3. You can set this parameter to a floating point value in the range 0.0 and 1.0.
UseJTAngularControl—Specifies the switch between the Creo application angle control values and the JT angle control values. Angle control values in the Creo application range between 0.0 and 1.0 while the JT angle control values range between 0 and 90 degrees. Set this parameter to true to use the Angular option and specify the JT angle control values to determine the tessellation quality.
By default, this parameter is set to false. Therefore, the Creo application angular control options, LOD1angle, LOD2angle, LOD3angle, and so on, with their values ranging between 0.0 and 1.0 degrees, define LOD generation.
After you create the jt.config file and select the Configure JT export with an external jtconfig file check box in the export profile to specify the use of the jtconfig file for the export of models to JT, you must set the following additional options in the export profile:
Path to jtconfig—Specifies the location of the jt.config file.
Name of jtconfig—Specifies the name of the configuration file in the path specified as the value of the Path to jtconfig export profile option.
The jt.config file is located in the /Creo_install_dir/text/jt/ directory. If you only set the Path to jtconfig profile option, Creo searches for the jt.config file in the path set as the value of this profile option. If you only set Name of jtconfig, Creo searches for the jt.config file in the working directory. If the jt.config file is not found in the designated path or in the working directory when you have selected the Configure JT export with an external jtconfig file check box in the JT export profile, the options set in the JT export profile are used for the export instead of the options set in the jt.config file .