Michael,

Thanks for your reply. I got a chance to check it myself in the meantime and noticed a restriction: In the case of the above example with extrusions, moving the source objects in the direction of the extrusion actually changes the extrusion height of the child object instead of moving it in that direction. I am assuming the reference plane of the original extrusion is considered another "source object" that would have to be moved along as well, which i'm guessing is not possible. Do you have a work-around for that as well? ;)

Michael H.

Hi Michael - it's not the reference plane of the original that is remembered in this case, it is the point that you picked to define the extrusion height.

When the extrusion is recalculated, it is using that same point to calculate a new height from the plane of the curve, that is why the height changes if you move it up and down.

There is workaround for this, which is to enter a specific distance for the extrusion height, instead of clicking a point to define the height. You can move your mouse around to get a good idea of what height you would like to use, but to finish the extrusion type in that height in the "Distance:" box in the upper-right corner, rather than clicking a point to finish the extrude.

That sets up the extrude history with a specific distance value instead of a point value, and it will then update later on using that same specific distance instead of calculating a new distance from the point.

I've been thinking of changing this to always save the distance value to history instead of keeping the point, because of that kind of unintuitive side effect that you noticed here.

- Michael

"I've been thinking of changing this to always save the distance value to history instead of keeping the point, because of that kind of unintuitive side effect that you noticed here.

- Michael"

i can see running into another problem this way. if one purposly extruded up to another object then move the curves you will lose your target for extrusion height, even when placement may be more important than distance. may i suggest a checkbox option to let the user decide, or leave it the way it is since it is much easier to extend an extrusion than to shorten one.

Hi xrok1 - yes there are potential problems either way. Sometimes I have to just kind of guess which problem will be more frequently run across and then avoid that one and live with the less frequent one.

Eventually I want to have some UI that will let you get in there and edit these history values directly, in this case with either placing another point above the curve's plane or by a specific numeric distance. That would be the general thing that would solve this.

One other idea that I had was if I left it as a point defined in history, that it might be a good signal when you select the input and output objects at the same time and move them, to transform the point values in history by moving them by the same distance. That would generally help with relocating some other kinds of history-related operations that work with points, like for example revolve. The points for the revolve axis in history can't easily be converted into some portable value unlike the extrusion distance.

- Michael

yes i like the idea of selecting input and output objects together to retain extrusion distance, or just selecting input curves alone to retain extrusion reference. this seems like it would be the most predictable and useful way to go.

P.S any plans to have some kind of mating relationships (concentric, parallel, distance) in the future?

> P.S any plans to have some kind of mating relationships (concentric,
> parallel, distance) in the future?

I haven't really thought very much about that...

It will probably be difficult for me to get into a full constraint solver type thing, but I think what you are talking about here could possibly be easier than that. It might be workable as a specialized transformation command. But it will probably take a while before I can get to that.

- Michael