NX3, converting spline segments to bezier curve?
NX3, converting spline segments to bezier curve?
(OP)
Hello, a customer is asking us if we can simplify a design we're currently working on for them. We're designing 2 scroll-like objects with extremely tight tolerances (to compress gas) using a custom grip program that generates the appropriate curves to create said surfaces.
They're asking us if we can take those curves and generate a parametric bezier type of spline to replace the hundreds of surfaces that are generated by the grip program.
has anyone delt with something like this before? can UG/NX even handle something like that? I can't recall that I've ever used a bezier type of spline outside of illustration software. I don't believe this type of solution would be easy to machine either (but who knows)
thanks in advance
They're asking us if we can take those curves and generate a parametric bezier type of spline to replace the hundreds of surfaces that are generated by the grip program.
has anyone delt with something like this before? can UG/NX even handle something like that? I can't recall that I've ever used a bezier type of spline outside of illustration software. I don't believe this type of solution would be easy to machine either (but who knows)
thanks in advance





RE: NX3, converting spline segments to bezier curve?
Anyway, here is what you do. Go to...
Insert -> Curve from Curves -> Join...
...and select the set of preferably at a minimum tangent curves, hit OK and when the dialog comes up asking for 'Resulting Curve Type', select the 'Advanced Refit' option and make sure that you have the 'Associate Output' option toggled ON as this will allow you to edit the resulting curve which you may need to do to get acceptable results (this is much better in NX 6 as all of the fine tuning options are included on the creation dialog rather than on the edit dialog as they are in NX 3). After the curve is created, if you received some kind of warning that some approximation was needed, you will probably need to edit the Join curve feature and tweak some of the options and tolerances. Note that if these new curves will have to be exported (translated) to another CAD system you may wish to inquire as the highest degree curve that they can handle and limit you final edit to that degree otherwise when these curves are converted they will just be broken back up into a series of lower-degree segments.
Anyway, I hope this helps.
John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/
To an Engineer, the glass is twice as big as it needs to be.
RE: NX3, converting spline segments to bezier curve?
There are probably areas where the multi faceted faces indicate a continuous surface, but if it describes a body with volume then there are probably also sides and corners. In resurfacing anything you often need to pick the slab surfaces from the blends extending the slab surfaces you create to intersections and applying the blends last. It is a whole process of working with the geometry seldom so easily answered as to find the one tool that is suited to your needs.
Without seeing such a model I couldn't say whether it is particularly difficult to fix, but just to let you know that the sort of thing you described sounds as if you will need to do more than just be able to join a few curves.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
RE: NX3, converting spline segments to bezier curve?
thanks again for all the help
steve