V3 beta Aug-24-2011 available now

 From:  Michael Gibson
4438.85 In reply to 4438.84 
Hi Greg,

> Along with keeping tangency between lines (something I think
> I remember you discussing) would it also be possible to "weld"
> endpoints together (as apposed to joining both entire lines)such
> that you can't accidentally move a line's endpoint off it's fellow
> while editing it?

You mean with a plug-in? That would be quite difficult to do with a plug-in because you're not talking there about just a new command to add that would perform some one time calculation - you're talking there about modifying the behavior of a large number of other existing commands like all transform commands, object dragging, etc...

So I can't see how that would be implemented as a plug-in, it would need to be a modification to some of the core MoI logic.

One problem with something like that it that it's not feasible to only implement just a welder - you may want to later on move its endpoint so you also need an unwelding mechanism to manage it as well.

Then there would be quite a lot of questions to answer for other kinds of editing tools - if you tried to move a line that had an welded endpoint, what would you expect to happen, should just nothing at all happen or should everything else that was connected to that welded point also move? If nothing were to happen, then that opens some doors to some extremely confusing scenarios, like say you receive a file from someone that happens to have these "welded" pieces in them, but of course you don't know anything about that yourself so you'll get extremely confused when you try to move some things around just in the course of examining the object and you don't get any response at all.

What about other kinds of editing tools than transformations like trimming or booleans - would they fail if they would produce an object that did not include an endpoint in that particular location?

Anyway, I can certainly imagine an enormous list of side effects and concerns similar to these ones...

For the most part your best bet to make sure things touch is to have object snap on when you initially draw it. If you don't have object snap on and you're just "eyeballing" things so that they look close to one another but are not actually snapped on to one another, then that will cause problems because there the ends won't be exactly touching if you do it that way.

- Michael