Hi Michael and All,
Please excuse the lateness of this reply, press of business has been extreme in the last two weeks. We managed to get through the deadline by using STEP files, but I seem to have discovered part of my problem. It is, indeed, the way I am putting shapes together that seems to be the issue. So, let me ask this question. Is the use of "JOIN" qualitatively different than using boolean joining techniques? Is there a script or some other way to test joins to make sure they are good? I know the script for identifying open curves, but this is different, is it not?

I really appreciate your help.

Best regards,
Bill

Hi Bill,

> Is the use of "JOIN" qualitatively different than using boolean joining techniques?

No, they both generate the same kind of result - a solid in MoI (and 99% of other CAD programs) is defined by a set of surfaces joined together at their edges to form a "watertight" skin. It should not matter which particular route you go through to get to that result.

> Is there a script or some other way to test joins to make sure they are good?

Yes, the first thing to look for is when you select an object look at the object type indicator in the properties panel in the upper-right area of the main window. That will read as "solid" if the object is a fully closed solid, and it will say "Joined srf" instead if it is made up of multiple surfaces joined together but with some open edges in it that are not joined to other things.

If you have an open object you can then set up a shortcut key that will highlight the "naked" edges (edges that belong to only one surface instead of being joined between 2 surfaces) so you can identify them. See here for how to do that:

http://moi3d.com/forum/index.php?webtag=MOI&msg=4869.5


> I know the script for identifying open curves, but this is different, is it not?

It's similar but yes a slightly different process - for surfaces/solids you're looking for unattached edges rather than just looking at endpoints.

- Michael

Hi Bill,

Just to add to Michael's post, you also have to remember when using NURBS modellers and you want to 'connect' pieces together you usually 'Boolean Union' Solids bodies and 'Join' Surfaces, you can also use the Boolean functions on surfaces, like if you have overlapping planar surfaces on the same plane you can 'Boolean Union' them together to get one surface, but you can't 'Join' Solid bodies.

Hope this clarifies further

Thank you both for your time. I was obviously not joining surfaces correctly, so am looking for much better results in the future.

Best regards,
BIll