Hi Nick,

> then the problem of no history would be solved (right?).

Not for the case of a hollow pipe, because that also takes 2 sweep pieces (an outer one and an inner one) and does a boolean operation to make the final result. So those 2 sweeps for that case are other intermediate pieces that would need to stick around in addition to the circles. So keeping all of that stuff would be a pile of extra stuff all stacked up on the same spot.

It basically needs a mechanism to kind of archive these intermediate objects so that history updates can find them without needing to have them immediately present in the model. Currently that archiving mechanism does not exist yet, so the history updates right now only work when all the elements in the sequence of the history are present in the model.

In the future I want to implement an archive mechanism which would then enable history to work in these kinds of cases. But because the archive may contain quite a lot of data in it, it's something that has to be designed quite carefully.


> Or are the circles drawn in some random location?

Yeah, they're actually created flat on the cplane way far off to the side so that the sweep "auto place" mode will kick in and they will get automatically moved and rotated to align with the start of the rail curve.

- Michael