Pick Axis to Scale Along.avi
You can determine the axis along which you will scale a selection.
The basic procediment is the same another vector operations:
make a selection, call context menu
and click on Scale Axis using RMB (right click).
Information Line, then, says you have to define an Axis.
Make this by selection one or more elements.
The Vector will be shown as a blue arrow.
When defined the desired axis, right-click to Execute
(as ever, Information Line will ask for this).
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It is possible to define not just the axis,
but still the point from which the scale command
will proceed: but this if for another video.