Hi JTB,

> I still can't reproduce what you think as a problem.

Well, that's the point, those steps aren't a problem currently in MoI because history is not automatically enabled for all operations.

If history was enabled by default for everything, then that's when those steps would create a problem - the second line would change when you modified the original instead of the second line staying separate.


> Generally I prefer to have all the options enabled and disable what I don't need.

But unfortunately this doesn't apply to all users - someone who is not familiar with history could be surprised that the other side of their trapezoid does not stay in place and they might not immediately know where to go to disable the option for updating it. Imagine if the copied line was farther away from the original one, it would be easily possible for the other one to change without someone noticing it, leading to a lot of confusion when they later returned to that area of the drawing. These are the ways that too much automatic history can lead to confusing people and getting in the way.


> Also, is it a two way relation? I mean, If I make it work, I have to modify the
> parent object, the copy, no matter which one?

No, all history in MoI is a one-way operation, where you can modify the input objects to a command and then recalculate the output.

For example - if you have 2 curves and use the "Loft" command to create a surface, you can later on edit the 2 curves which were inputs into Loft, and then history will recalculate the Loft. But it isn't possible to edit the resulting Loft surface and have the changes apply back to the input curves.

I mean for example if you trim the Lofted surface, how would you expect that edit of the surface to change the input curves?

I can see doing something special specifically for instance copies where there could be a 2-way relationship. But that would be something very specialized just for that one operation and would not apply to history in general for any command.


> I think (since there is no modifier stack or modeling history recorded in MoI yet)
> the simple copy and the instance is what you can have in MoI. This would be just
> an option in the copy command

Yes, I can see adding this in to the copy command in a future version.

What would happen though is that the "create instance" mode would use a new instancing mechanism which does not currently exist in MoI. This would actually be a different mechanism than "History".

For version 1.0 of MoI, instancing and copying and just generally creating layouts of big scenes just isn't really the focus yet - the focus is just on modeling tools for creating a single object right now.


> I am very sorry if sometimes my english makes me sound like teaching something to you.

Don't worry, I don't think that! :)


> I appreciate your hard work and my intention is to help only.

It does help! And it definitely gives me a lot of ideas for future enhancements. Some of these will take a while before they will be possible for me to work on... Since I have such limited resources, there is just a pretty big limit on the amount of stuff that I can accomplish within a relatively short period of time. Some things just have to wait until future releases...

- Michael