Larry,
It's "sortof true" what you are describing, but only in the sense that you are misusing the toolset.

You will want to adjust your workflow if you want to work in a "direct editing" type of flow.

So, if you want to "draw objects, then fool around with them to see", you can plan for that and use MoI's history mechanism to do that.

A lot of operations have history enabled by default. So if you sweep a profile along a path and generate a result, you can then edit the profile and path curves to manipulate the swept result.

So for your example of the cylinder, you could generate a loft with several sections, then manipulate away on the curves that generated the object...

Mostly though, you are approaching MoI as a direct editor, which it really is not.....

If you want MoI to be 123D, that probably wont work out for you. If you want to present examples and ask to learn MoI, you can get some good results...

Hi Larry,

> I've tried using the move tool to move faces without separating them from the
> solid, which did not do anything.

Yeah currently the Move command doesn't know how to move a sub-selected face. That is something I want to add in the future though.

Probably the best way to make a new longer object like you're describing is to just extrude a new one from the original curves. There is not a lot of focus currently in MoI on editing an existing shape like you're trying to do, although the extrude command can do some of that.


> And then I tried to use the extrude tool. Which did not work for elongating a rifled
> barrel. The rifling, which was of ratchet type, had no twist to it yet but the extrude
> still failed. It would not extrude one of the ends of the rifled barrel.

If you can post the 3DM model file with the object that failed to extrude that would probably help to give some more information on what's going on there.


> I can use extrude to resize simple shapes but even then, it seems to leave an edge or crease
> behind where the walls used to end before I used extrude to lengthen the solid.

Yeah when doing the face extrude, it's the same thing as doing a regular extrude followed by a boolean union - currently MoI will combine coplanar planes into single faces in boolean union but not in situations like cylinders. Is there a particular reason you're worried about the additional edge that you're ending up with there? That still should be an ok model despite that. If you want a longer cylinder without any of those edges I'd just extrude a new one from the original curves.

- Michael