Hi JTB,

> Undo is not always the solution because sometimes I 've already
> created 2-3 objects before see the mistake.

There is a way to solve this using undo in combination with copy and paste.

What you do is undo back to where you have the proper setup, select the solid and the generator curve there and do an Edit/Copy (or Ctrl+C). Be very careful at this point not to make any changes, because if you make any changes you will lose the redo stack. Then redo all the way to the end to restore everything. Now you can do an Edit/Paste (or Ctrl+V) to recover the older version.

This procedure is useful in a lot of situations where you might want to sort of "resurrect" an older version of something without losing new changes.


But I agree that it would be good if there was a way to have the curve bundled up with the solid somehow so it couldn't get disconnected so easily. I've thought about some possible mechanisms for this before a bit, because it would also help to preserve the history chain through several other operations than dragging as well - for instance right now if you do a fillet on your solid it will also break the chain because conceptually the fillet operation deletes one solid and replaces it with a new one, which in this respect is similar to what dragging does. The deletion step is what breaks the chain.

But it is not going to be easy to set this up. One potential problem is a large increase in file size since there may end up being a lot of extra shapes invisibly attached on to things. Right now it is a total "What you see is what you get" system, where there isn't a bunch of extra things hidden away. So I think that something like this needs to have additional UI mechanisms, like a browser tree that will let you examine the hidden components of an object. All of this adds up to a large quantity of work though, which pushes it out of the scope of what I'll be able to do for the V1 release, this stuff will have to wait until a little later on.

- Michael