Hi Michael,

Thanks for that information. I'm starting to get the hang of this program and in many ways I like it.

As with any large program, there are things about the documentation that are unclear or absent for the newbie, but become routine for the old-timers. For example, I now realize that MOI doesn't really know something is truly "solid". In this context, "solid" simply means that a volume of space is completely bounded by surfaces that all meet each other (the term of art is that it's "Manifold"). I proved this theory to myself by using "Draw Solid" to make a cylinder, and then cutting that cylinder. The result was not a shorter cylinder, it was a cup. So to answer my question, "Creating this as a solid" means creating faces that all intersect, or meet each other with no gaps. Faces can be created with "Network" or "Planar" commands.

I now realize that you can constrain the two endpoints of a freeform line to be locked onto the ends or intersections with other lines in the drawing, but you can't constrain a midpoint to intersect with the end of another line. So the "ribs" of my umbrella must each be independent lines, tied to the base on one end and tied to each other at the apex.

So armed with this knowledge, I've created a new version of the wedge from scratch. The "X" at the top doesn't bother me.

But for the life of me, I can't figure out how to make the planar base properly attach to the umbrella top. Both constructions are using exactly the same closed curve, so to my mind they should automatically intersect perfectly. The "Join" command doesn't fix the problem. I even tried deleting the line around the base and using the "Planar" command with the umbrella selected; it creates a membrane on the base but it's still not correctly attached to the umbrella. The problem shows up with the use of your reveal command. I can't figure out how to fix that. It's perfectly true that the part is not manifold; if I export it as an STL and check it with Netfabb, that program also flags it as not manifold.

In another post, you had a link to a zip file that would create a "plug-in" that would help resolve this kind of problem (I guess) but I can't find any documentation about how to install a Plug-In into MOI.

So can you help me perfect my work method and know how to get the base connected to the top?
-Jay

Hi Jay,

re:
> For example, I now realize that MOI doesn't really know something is truly "solid".

Actually it does - an object that has a watertight skin will be recognized as a solid, it will show the object type as "solid" here:


it will also work with the boolean commands and in v4 you can calculate the volume of it.


> I proved this theory to myself by using "Draw Solid" to make a cylinder, and then cutting that cylinder.

Your result will depend on what tools you used to do the cut. If you use the Edit > Trim command, that one is focused on surface level operations and not on volumes. The boolean commands are the ones that work with volumes.


> So to answer my question, "Creating this as a solid" means creating faces that all intersect, or
> meet each other with no gaps. Faces can be created with "Network" or "Planar" commands.

If you have constructed several surfaces that touch each other with no gaps, you can use the Edit > Join command to glue them together into a connected watertight skin and that will result in a solid.


> In another post, you had a link to a zip file that would create a "plug-in" that would help resolve this kind
> of problem (I guess) but I can't find any documentation about how to install a Plug-In into MOI.

Check out the Frequently Asked Questions page: http://moi3d.com/FAQ#Q:_How_do_I_install_a_plug-in_script.3F


> So can you help me perfect my work method and know how to get the base connected to the top?

You would normally use Edit > Join to glue the 2 surfaces together, but you have too large of a gap between them for it to be able to join.





The gap is a result from 2 of the curves not touching the bottom one:





In the attached 3DM file I've tuned those curves up to make them end directly on the bottom one, then did Construct > Network to build a network surface then selected the surface and used Construct > Planar to fill in the planar bottom opening to make it a solid.

Hope this helps!

- Michael

Thanks again. I'm getting the hang of this!