Longitudinal Flooring - main settings for the layout of Structural Framing families.
Type - select Structural Framing family which should be used for slab layout
Array 1 - settings for layout
Array from Start, End - layout of Structural Framing elements will start from one side of the Floor and will continue to the other side of the floor with defined spacing and number of elements. Start is the location of Span direction symbol in Floor boundary.
Spacing - distance between Structural Framing elements.
Number - number of elements that will be created starting from selected side. It could be any big number if you want to fill the whole reference slab; once it reaches the end edge of the slab, it will not generate more slabs than needed.