Spline through parametrzied number of points

[PrintScaffold]

Greetings all!

Is it possible to build a studio or fit spline through control points, the number of which is parametrized and therefore is not known in advance and can vary? Or is it too much to ask?

Industry creates wealth!

 

[cowski]

...not known in advance and can vary

I'm not sure I understand exactly what you are getting at. If you are constructing a spline through points, at least some of the points must be known at the time you create the spline. You can later edit the spline to move, add, or remove points.

Perhaps if you reword your question and give a more concrete example, it would help us help you.

www.nxjournaling.com

 

[jerry1423]

don't forget to mention the version of NX that you are on !

 

[PrintScaffold]

at least some of the points must be known at the time you create the spline

Many thanks for stating the obvious!
I'm not sure how to re-word this, because what I already stated is rather clear. Don't have time to build a demo model at the moment. But imagine a pattern feature which can output different number of points depending on the pattern definition. First time it can be 20 points, the other time it can be 10. Can spline go through the exact number of points each time I update the pattern definition?

Industry creates wealth!

 

[PrintScaffold]

NX8.5 and NX9

Industry creates wealth!

 

[Xwheelguy]

I would have to ask myself this:

How would the spline know in which order the points were added or removed? If you begin with a 10 point spline and add 10 more points is the 11th point the new first point? Does it now come after the 2nd point? Just putting points on a screen isn't going to define a feature with which they are used to create.

My point (no pun intended) being that there probably isn't enough information being given for the associative spline to derive which points to pass through and what order to pass through them. When you create a curve on the screen, an Extrude feature won't just know to use it (unless you're using a Curve Rule when the Extrude is created and the new curve touches the existing set of curves and meets the Curve Rule requirements).

I doubt that a Spline feature is going to be smart enough to know which points to use and which order to use them.

Tim Flater
NX Designer
NX 8.0.3.4
Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB

 

[JohnRBaker]

Tim pretty well hit the nail on the head. Note that there are NO Spline options which will REMEMBER HOW it selected a series of points although there is an option to 'chain' a set of points, but once selected, this 'chaining' behavior is NOT saved as part of the Splines definition. In other words, once created, when a 'chained' Spline is edited or updated, it does NOT try to 're-chian' some new set of points.

If you want the behavior that you're describing, your best bet would to create an NX Open application which could be run to update a curve using some sort of 'recipe' for how to find a new set of points to be used. That being said, even this approach wouldn't give you a whole lot more than what you already have if you were to simply interactively edit, as was suggested previously, the spline and simply add/remove any relevant points.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
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[Shadowspawn]

hmmm... maybe use external .xls file(s) to define the x/y/z points of associative points in a sketch, then use associative splines to those points? I/we/the company I worked for... did this in a past life so I know it's possible. We had a seed file based on 100 points per spline.... and removed "whatever" points weren't needed from the splines (in the subsequent .xls files defining the points... what ever points weren't needed were 0,0,0 and the points would update... <shift> window those points to remove from the splines to update after substituting new xls files...)

Regards,
SS

CAD should pay for itself, shouldn't it?

 

[JohnRBaker]

Yes, that would be one way to approach this issue, 'overdesign' the spline sufficiently so that any real curve would have less then the number of points used for the 'template'.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.