Seismic Load Type Directions

To aid in the load combinations per ASCE 7-16, load cases marked with the "seismic" load type are now divided into "horizontal" and "vertical" directions.

This is used to accommodate load combinations which separate between vertical and horizontal seismic directions. With "Y up" models, the horizontal seismic loads act in the global X and Z directions. When the "Z up" option is used, then the horizontal seismic loads act in the global X and Y directions.