1. Open the 3d model view
2. Open the Drawing Extraction Manager. (Content > Extract Drawings)
3. Select the Roof and use the Copy Drawing Definition (2nd icon on toolbar) to make a copy.
4. Rename the new drawing definition to something unique, say “Roof Framing”.
5. In the Region tab you can change the location of the section elevation and the depth. You can change the elevation of the section by using the Move Section button or, more easily, by just keying in a new elevation in the Distance and Orientation field. Next, change the depth of the section by keying in a new value in the Forward View Distance field. Make it larger enough to extend through the volume of interest.
6. Save the new drawing definition.