Hi Val - for making reference lines use the "Construction Lines" feature.

This is enabled when you are in a drawing command by pushing the mouse button down, then holding it down and dragging away, instead of a push and release.

When you hold down and drag, you will create a construction line which can be used for snapping purposes like alignments with an edge, extensions, intersections, etc...

For more information, see the doc file here: http://moi3d.com/beta/moi_command_reference2.zip , under the topic "Construction lines".

One really nice thing about MoI's construction lines are that they don't jump up completely automatically - stuff that is triggered automatically can tend to get frustrating and get in your way when you don't want it. With a construction line, it is only triggered with that dragging gesture so it stays out of your way until you call on it, but it is also really easy to call on.

Also other kinds of reference line things are usually limited to radiating a line out from one single point, just along major axis directions. With MoI you get to choose 2 points for the reference line, the spot where you clicked down on, and then the point that you released the button up on.

Since your line is defined by 2 points (instead of one point + axis directions) you can have it angled at any direction, and this also gives many other abilities like finding the midpoint between any 2 points by using a construction line, doing mirrored points, setting up divisions like 1/5 increments between 2 points, capturing a distance and applying it to a different location, and more... This is all covered in that doc file above. Also see the new tutorial video here: http://moi3d.com/forum/index.php?webtag=MOI&msg=975.1 , it uses construction lines in it as well.

- Michael