When preparing the model in a CAD software, draw it in a hanging position displaying the front view. This means that the pan axis is Z aligned, and the tilt axis is X aligned in the model's coordinate space.
For detailed instructions, refer to the GDTF wiki: https://gdtf-share.com/wiki/GDTF_File_Description#Model
The link between geometry and model is defined in the geometries.
Define the models in the Models tab.
To add a new model, click Add Model.
The Add Model window opens.
Enter the model Name.
Enter the model Length, Width and Height.
When the checkbox "Use File Dimensions" is activated, the dimensions of the 3DS model will be used.
To open the Primitive Type dropdown menu, click the Down arrow.
The Primitive Type dropdown menu opens.
Select the geometry model type from the Primitive Type list.
To upload the 3D model from your disk, select 3DS File .
To use one of the GDTF default models, select Cube, Cylinder, Sphere, Base, Yoke, Head, Scanner, Conventional or Pigtail.
Hint: If you do not have a 3DS file, use a predefined default model like cube, cylinder, etc.