Hi Paul, the extrude + collapse thing goes like this:

Starting with a curve:



Extrude with caps turned off (or use Edit/Separate to break into individual surfaces so you can control point edit):



Now you can select it, and turn on its control points with Edit / Show pts. Switch to a side view and select the top set of points like this:




Now run the Transform / Align command. This allows you to line up objects or points. By default it is in horizontal alignment mode, which forces points to collapse down to a straight horizontal line. So if you pick a point in the middle of the object, the result will be this:



All the selected points were collapsed down to a horizontal line. Now run Transform / Align a second time, and switch the alignment option to be "Vert center" - this will now align everything to a vertical line, if you pick another point in the middle, that will cause the points to be fully collapsed together:



Once the points for one surface edge are fully collapsed down to the same spot, you can then drag that point to some location if you want.

That is the same surface that would be generated by a loft to a point (which is certainly more convenient and I would like to add that).


I do also want to figure out a way to show the start point of a curve, I just haven't quite figured out a good spot to place that yet - I'm going to be working on a kind of properties panel for selected objects in v2, and I want to figure out a place on that panel to pop up a menu with a bunch of additional stuff for an object, this could probably go there.

- Michael

Hi Micheal,

>> All the selected points were collapsed down to a horizontal line. Now run Transform / Align a second time, and switch the
>> alignment option to be "Vert center" - this will now align everything to a vertical line, if you pick another point in the middle,
>> that will cause the points to be fully collapsed together:

I see what you mean now....Thank You

I think this method would be fine for visual rendering later but stacked control points are never a nice thing when doing more
modeling using that surface ??.

>> I'm going to be working on a kind of properties panel for selected objects in v2, and I want to figure out a place on that panel
>> to pop up a menu with a bunch of additional stuff for an object, this could probably go there

Sounds good. May I ask will that show things like number of selected items, properties of item, validty etc ??

All the best,

Hi Paul,

> I think this method would be fine for visual rendering later
> but stacked control points are never a nice thing when doing
> more modeling using that surface ??.

Yeah you should avoid stacking points in the middle of a surface, but it is ok if it is an entire edge at the end of a surface. For instance a sphere has that same kind of collapsed-together edge in it, and Loft to a point will end up doing the same thing.


> Sounds good. May I ask will that show things like number
> of selected items, properties of item, validty etc ??

Yeah, hopefully a bunch of stuff like that, but probably focusing on properties at first.

- Michael

Loft to a point will end up with one cv in the middle no ?

As usual many thanks!

Rgds,

Hi Paul,

> Loft to a point will end up with one cv in the middle no ?

It'll look like that, but it is the same bunch of points all stacked up on top of each other. It won't be unusual for a NURBS modeler to treat a set of stacked up points on an edge as a single point in the UI when it comes to selecting or moving it, but in actuality it has the same structure as you see here.

In Rhino if you do the loft to a point, you can see the stacked up points by selecting the single point, and then use the "Smooth" command, that will slightly separate them and you can see the individual ones that way.

- Michael

Hi Michael - I gotcha now !

Many thanks for helping me understand this better from the MoI himself.

Rgds,