Hi NightCabbage - re: Join for curves

Yeah join for curves is meant to join segments that touch end to end into a single large (possibly closed) loop.

For curve joining to work properly, you should only have 2 segments touch each other at any one point. You wouldn't use curve joining on a branching structure like 12 lines arranged in a cube wireframe.

Instead of trying to make all those individual line segments, the way that you would generally make a sloped cube in MoI would be to have 2 rectangles, like this:



Then select them both and run Construct / Loft to build the result like this:



You generally try to focus on making some curves that are cross-section profiles like that rather than trying to make a branching wireframe structure like you were talking about with the 12 individual lines.

Hope that helps!

Also have you already seen the video tutorials which are available here:
http://moi3d.com/1.0/docs/tutorials.htm

If not, those are worth checking out, they go over all the steps to build some simple example models.

- Michael