Hi Eric,

> It seems that if I keep the original wall base lines that I
> can then turn on the control points and simply move a
> selected set of them to elongate a wing of the house
> ... say by 4 feet.

Yes - this is a history update operation in action. When you did the extrude to make the walls, that extruded result is linked to the original input objects so if you edit them the extrusion will update automatically.

If you plan on updating the model later it is a good idea to keep those around, you can hide them to get them out of the way if you want.

It is not really as easy to edit a solid directly in the same way.


> Suppose that after the model is fairly far along the client asks
> that the living room be made longer ... is there a simple way
> to do that?

It is possible, probably the most basic approach is to duplicate the edges of the solid by selecting the edges and doing a Copy/Paste, then delete the solid, turn on control points of the curves, stretch the curves, and extrude some new walls to match your new size.

You can also use some boolean operations to break the solid into pieces in strategic areas to make the edit that you want.

That method would work like this:

Draw a couple of lines in your model to isolate a section that can be scaled in one direction without any problems:



Select your solid walls and run Construct / Boolean / Difference and pick the lines as the cutting objects. This will dice the walls up into pieces. Now you can grab the end piece and slide it over to your desired new location:




Now you can select the 2 center pieces, and use the edit frame to scale them only in the horizontal direction until they match the moved piece, like this (note, click once on the scaling grip before you drag it to switch the scaling origin to the corner style instead of center style):





Then select all those pieces and use Construct / Boolean / Union to glue them back together into one piece again, I think that should create the final result that you want there.

If you want to shorten an area you can use a similar approach where you just cut out a spot and delete it, and then drag the remaining pieces together and then union.


Also another different option is to use Edit/Separate to break the model into individual surfaces, you can then turn on control points for the surfaces and drag the surface points around. In this case you'd probably delete the top and bottom cap surfaces and then rebuild them by selecting the edges and running Construct / Planar when you were finished re-arranging the surfaces.


But I think that by far the easiest method is the one you originally mentioned of keeping your original curves around and editing them to get the history update.


There are some other programs out there that are much more focused on editing a solid in these kinds of ways, if you expect to need to make these kinds of edits on a regular basis, it is quite possible that MoI is just not really the right software for you since it is not very focused on that particular kind of tasks currently. You might want to look at other software that is more focused on that kind of "direct solid editing", such as SpaceClaim, Siemens NX, Solid Edge, or Kubotek. Those programs have put a lot of emphasis on doing those kinds of edits - MoI is instead much more focused on doing the initial drawing as quickly and easily as possible.


I do want to improve this kind of editing in the future, it will probably be in some kind of deeper history recording that will keep those original input curves recorded for you and available to go back and edit even if you delete them in the current model snapshot.

- Michael