While the Truss tool does not create log trusses, you can download a Catalog of Components that include a selection of log trusses ready to be placed in your plans.
This article walks you through preparing the structure, placing trusses, purlins, and adding a roof over the top of log trusses.
Roof trusses are generated in the space between the roof planes and the ceiling planes below. When a vaulted ceiling is created scissor trusses are used.
For energy efficiency, some areas recommend an energy heel, or raised heel, so that there is not a cold spot in the intersection where the roof meets the wall.
You can create exposed trusses by creating a ceiling to define where you want the trusses' bottom chords, drawing the trusses, and then removing the ceiling.
Roof trusses are defined by the position of one or more roof planes above and one or more ceilings below, so both must be in place before a truss is drawn.