Hi All,
Apologies for the long delay responding to this one - there's some problem with my notifications. Ted's away so I'll just give a quick update .
When we were doing the slope video we realised that the current option to define a slope is basically quite difficult to use. We decided to update the software as described by Ted above to make it easier to understand. Unfortunately this pushed back the tutorial because we didn't want to release a video that would be out of date almost immediately.
The development's now complete on this update, and it's a big improvement. The old option to define three points is still there, but there are new options to define the slope direction with an arrow. It's currently being tested and the update and video should be up within 2 or 3 weeks.