If you have a DirectConnect installed, you are now able to export files in the JT file format.
When you open the option window for File > Export > Active As or File > Save As , you will see JT in the File Formats pull down menu.
DirectConnect also gives you access to the AlToJt command-line utility which you can use to translate a wire file to JT format from the Command Prompt window, without running Alias. Type AlToJt -h to see a list of all available options and their definitions.
Below is a description of all the options in the option window, as well as their command-line equivalent.
This option allows you to organize your data by GEOMETRY, SHADER, LAYER or SBD structure type.
GEOMETRY – One DirectModel node object (.jt file) is generated for each geometry object. There is a one to one correspondence between a geometry object and its DirectModel part.
SHADER – One DirectModel node object (.jt file) is generated for each Alias shader.
LAYER – One DirectModel node object (.jt file) is generated for each Alias layer.
SBD Structure – The SBD structure in Alias is first translated to an assembly structure in DirectModel, then one DirectModel node object (.jt file) is generated for each geometry object.
This option allows you to organize your data in a multi-level hierarchy structure. Organize Data First By creates the first hierarchy level, and Organize Data Second By lets you control how the second level of the hierarchy is constructed. This option is only available when Organize Data First By is set to SBD Structure, SHADER or LAYER. The following table shows the possible combinations:
Organize Data First By | Organize Data Second By |
Geometry | None |
Shader | Layer / None |
Layer | Shader / None |
SBD Structure | Layer / Shader/ None |
Command-line equivalent: -e2b for SHADER and -e2l for LAYER.
This option applies to layers that have mirror symmetry turned on in Alias.
Off: The instanced geometry is not exported. This is the default.
Merged: The instanced geometry is duplicated as additional geometry through the JT translator (AlToJt). Each instance is merged into the same node as its original geometry in the JT viewer program.
Unmerged: The instanced geometry is duplicated as additional geometry through the JT translator (AlToJt), but the original and instanced geometry are located in separate nodes in the JT viewer program.
The Unmerged setting can be over-ridden on a per layer basis based on the layer name. If the layer name ends with -jtmrg, and symmetry is on for that layer, then geometry in that layer will be exported as if Export Symmetry was set to Merged.
You can choose between three different tessellators:
Fast – uses the same tessellator as Hardware Shade with the Fast option selected. This is the default. Command-line equivalent: -to.
Accurate – uses the same tessellator as Hardware Shade with the Accurate option selected. Command-line equivalent: -ta. (This replaces the old AG tessellator.)
Current – this should give you the same tessellation as in Hardware Shade when Show Triangles is on (this option appears when Quality is set to User defined). Command-line equivalent: -td.
This option applies to Fast and Accurate tessellation modes only. It indicates the number of tessellations that will be saved in the JT file (1, 2, or 3). The default is 1.
The first tessellation is always the most detailed, and uses the Tessellation Tolerance value. The second and third tessellations are progressively less detailed, and use larger tolerances.
The tessellation tolerances for tessellations 2 and 3 are obtained by multiplying the tessellation tolerance of level 1 by scale factors provided by environment variable ALIAS_ALTOJT_LOD_MULT.
The default value for this variable is the following string: "1.0, 2.5, 10.0". The first number must always be 1.0. The second and third numbers are multipliers that are applied to the Tessellation Tolerance to provide the tolerances for the second and third tessellations respectively.