To create a parametric truss model, use the following procedure.

1. Select Truss Models from the Model Type drop-down list.
2. Select one of the parametric truss types by either:

   double-click on the type of model

   or

   click-and-drag the model icon into the view window

   • Pratt Truss
   • Warren Truss
   • Howe Bridge
   • Lattice Truss
   • Howe Roof
   • North Light
   The Select Parameters dialog opens.
   
3. (Optional) Type a Model Name.
4. Type the overall truss Length, Height, and Width distances.
5. Type the No. of bays along length to define the number of equally spaced bay along the length of the truss.
6. (Optional) To use unequaly length bays:
   1. Click the […] adjacent to the No. of bays along length field. A dialog opens with the length of each bay.
      
   2. Type the length of the different bays in the corresponding Length cells.
      Note: The total length of the bays must add to the overall length specified in the Select Parameters dialog. The precision should be to about 3 decimal places (e.g., 11.333).
   3. Click OK.
7. Type the No. of bays along width to define the number of transverse bays.
8. (Optional) To use unequaly length transverse bays:
   1. Click the […] adjacent to the No. of bays along width field. A dialog opens with the length of each bay.
   2. Type the length of the different bays in the corresponding Length cells.
      Note: The total length of the bays must add to the overall width specified in the Select Parameters dialog. The precision should be to about 3 decimal places (e.g., 11.333).
   3. Click OK.
9. Click Apply.