To edit the bottom chord of the truss (ceiling plane) use the Ctrl (horizontal) and Shift (vertical) keys as modifiers to your left mouse clicks. This is helpful when the two truss bearings are at different heights, or to create a vaulted or coffered ceiling as shown below. You must start with the left end of the truss first.
You will need a workline, wall or beam that is between the two truss bearing walls, usually parallel to these walls. This will be used for the ceiling step.
Start the Bottom Chord Edit tool on the Roof ribbon, Truss tool group. (BC Edit)
- Ctrl + Left mouse click the first wall where the left end of the truss rests. Either the high or low wall. it doesn't matter. This establishes the horizontal ceiling plane.
- Shift + Left mouse click the line or wall where the step occurs. This defines a vertical shift in the ceiling.
- Ctrl + Left mouse click the workline with a "z" offset defined above the wall height. (10' 6" in this example.) This brings the ceiling plane back to horizontal at the height of the workline, wall or beam.
- Shift + Left mouse click the next workline to define another vertical shift in the ceiling.
- Ctrl + Left mouse click the second wall to establish the horizontal ceiling plane at the wall height. (Right end of the truss.)
- Drag the mouse over the trusses you need to modify.
The view of a selected truss in the 3D view should show a truss with a coffered or stepped bottom chord.