I have been meaning to post about this for a while, there as been another thread showing concerns but as that as just died away, then I thought time to post my questions/concerns.

Interpolate spline.

The default behavior made when closing a spline, this I have never understood in VC, certainly as attempting to correct/change the end positions to align as required is, well, can be difficult at best.

Pic1 show an 8 point interpolate closed spline. This outcome is not wanted,.. is there another way to close the spline? Yes, I can edit the spline and set the start/end points so that the joining angle is the same, and works OK for a planer(2d) spline, but:-
Creating a 3d closed interpolate spline. As you will see from pic2, again the closed spline is not what I would expect, I can again go into the object info and change the start/end angles but attempting this will not give what is required.(pic03 / pic04).
I have always had the expectation that a closed spline will be closed and all points on that spline by default will act on the spline equally, but this is not the case with VC.

So, I imported the curve from another application that does close the spline as expected and imported that into VC (pic05), but, on segmenting the spline (not at the join) then the actual spline is split at the join with loss of curvature/tangency (pic06),... not workable as there is no way to re-align curvature/tangency of the endpoints accurately.

- Steve

Very good work Steve, to simply show closed spline flaws.
I fully support your request.
JL

Hi jol,

To close an open spline, select the spline- show points. Select "connect" then click on the 2 end control points, it will close,.. but make sure you click the control points and not the spline. The first endpoint you select will stay in position, the second point will then move.


- Steve

Thanks Steve but I have workarounds .. I am just asking for normal snapping behavior

Hi Steve .. I didn't realise that translate allows a snap to the other end !! Thanks

I usually make the point active by fence selecting it - then I drag it onto the other end point .. there seems to be a problem with snapping when you do so

Normally I place a point - and then snap to that

Anyway .. hopefully Tim can make it behave as other points do !?

>> you have to "show points" - "Translate" and snap the end control points together.

I think that's my point .. I shouldn't have to show points - and I should be able to move with the Select tool .. as well as the translate tool

I should be able to select, move and snap a start point to an end point as I would any other

Sorry Steve - I think I miscommunicate

I want to move a spline endpoint to it's start point

I want to do it just like I move any other spline endpoint - using the normal select tool

First .. I box-fence-select around the area of the endpoint until the endpoint lights-up

Then I just drag-move it to where I want it - normally it snaps to exactly where I want it !

On this occasion however, alas - it does not .. it's a simple exception that needs recifying

I shouldn't need to alter my method just because I want to snap to a particular object type (when all other object types are included)

Fortunately, my extensive Hollywood training allows me to make this short, yet captivating movie to demonstrate my problem

Again - I am aware that there are workarounds Steve .. I appreciate that !

Damn - forgot to add the credits !

I was hoping for some possible answer to the problems shown in the first 2 posts on thread.


- Steve

>>Interpolate spline.

>>The default behavior made when closing a spline, this I have never >>understood in VC, certainly as attempting to correct/change the end >>positions to align as required is, well, can be difficult at best.

Closing a spline currently preserves the start tangent and making the end tangent match. In the video below, I'm exploring using an average slope based on the points before and after the shared point. This seems to produce a smoother spline (relative to curvature distribution...)

The video also show some improvements to dynamically creating splines.

http://www.csi-concepts.com/Dem...harkFXV6/splineClose.mov


Tim

Yes, I understand what is happening as it does put this forward in the help files.

That is what I am actually used to seeing as default behavior in other cad systems I have used.

Thanks for looking into this and hope to see this option available in a future update/patch.


Regards,

- Steve