Sketchup
Section planes are so easy to create, and use, this little slide presentation uses a simple video to show how, its not the only way to create section, the Position Camera tool is also usefull, but needs to be saves as a scene, as one altered there is no saved section unlike in the section plane tool
A very nice way to add depth to an elevation by fogging the back of an elevation
References
Books
- Sketchup for Dummies