Hi Dan, thanks very much!


> Feature request: In a reply to Daniele (BADANS) posted on
> 21 September 2007, you mentioned the possibility of including
> a Tapered Extrude in a future version of MoI. Is that still
> a possibility?

It will definitely be in at some point!

I think this is still in the cards for v2 but it will probably be near the end... It also depends a bit on how long some of the other v2 pieces yet to be done take up. If some other pieces take too long I'm not sure that it will get in for v2, but we'll see.


> Question 1: When offsetting a curve, such as ellipse or freeform,
> the resulting new curve has so many more control points,
> especially along the tighter bends, even though the newer
> curve doesn’t seem to be that much more complex than the original.

I did a little bit of loosening up of those in the last v2 beta, there should probably be a somewhat less density with this version but still not exactly simple.

The fundamental problem is that the offset of a NURBS curve is not another NURBS curve except in certain special cases. I mean a mathematically exact offset. The offset has to be formed by a kind of fitting process to sampled points, and those kinds of fitters tend towards dense output, it is difficult to do a fitting mechanism that only uses a smaller number of control points.

It may be possible for me to improve this in the future by licensing some other toolkit's fitting mechanisms, but it is not a very easy problem to solve very soon though.

The density usually comes by trying to get an accurate result, the fitting process has to refine further and kind of getting the last 0.001 units of accuracy involves putting in more points.



> Question 2: <..> When I offset a curve, then try to move the
> original, there remains a connection between the original and
> offset curves, such that moving the original changes the shape
> of the newer curve.

This is actually a feature :) - it is the history mechanism in action where editing an input to a command will do an automatic recalculation of the command and update the result.

For another example, if you do an extrude of a curve, you can edit the curve and the extrusion updates - it's the same thing happening in this case but with the offset updating.

You can turn off the history update of the object to stop this - to do that, select the offset result, and then go to Edit/History and pick "Disable update".

With history updating disabled on the output object, it will not get recalculated when the original object gets edited.

I've tried to have history updating turned off by default for several kind of "low level" working commands like Copy for instance. Maybe it should be off by default for Offset curves as well, I'm not quite sure..

Anyway, that's what is happening in this case.

- Michael