I created 4 rectangles which intersect with the goal of unioning them and then extruding to create 4 walls. The union on the rects isn't connecting one of the outer corners, so it comes out wrong. I've got several workarounds that I can do so no big deal but I wanted to try this as a method of accomplishing this task to see how it'd work.

Hi Supagoat, thanks for posting the problem file. One thing that you can try with boolean union if it goes wrong is to do the union on just 2 adjacent pieces at a time, which in this case does help out.

From what I've seen in the past, the geometry library that MoI uses can be sensitive to cases like this when the first 2 pieces that it tries to union together are the ones that don't touch each other. When you grab only 2 adjacent ones at a time, it then avoids that particular case.

The same thing can also occasionally be a problem with union between solids as well. For solids it tries to sort a batch of selected objects by initially starting with the largest object so that if you're doing a union of a lot of little things hanging off one one big block that will avoid trying to process the little non-intersecting pieces with each other first. But if you have a kind of chained sequence of objects like you have here that can benefit from "2 at a time" unioning instead.

Hopefully at some point in the future I'll be able to dig into it and try to improve these cases, it's a quite complex area to investigate though and so there is a lot of time involved with doing that.

By the way I've just figured out a fix for the "straight sections" loft problem that you reported previously in another thread, that one will be fixed for the next v3 beta.

Thanks,
- Michael

Also you may have done this as the other way that you mention already, but often times it's more convenient for making "wall thickness" to create one outer or inner piece first and then use Construct > Offset to build the other matching one.

- Michael