Spline creating a non-planer surface

[johnwizz]

Can anyone tell me why a spline that is created on a plane and extruded along that plane does not creat a planer surface? If I did the same thing with a line, no ploblem but as soon as I add curvature to the line it doesn't work. Let me clearify a little... The surface may be all in one plane, but I cannot use it to infer a CSYS like I can a normal planer surface.

FYI. I am running NX9, but I don't think that matters.

Thanks,
John

 

[cowski]

Check the desired "freeform construction result" option in Preferences -> Modeling -> Freeform.

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[johnwizz]

Cowski, thanks for responding. Honestly, I'm not sure what I am looking at there. What would change the results I am seeing?

 

[cowski]

Is the option set to "Plane" or "B-surface"? I'd guess your current setting is "B-surface"; if you set it to "Plane" and the result of the operation (the extrude in your example) can be converted to a planar surface, it will be planar. Otherwise it will result in a B-surface, which is a general surface type which does not have a well defined csys for the entire object like a planar surface does.

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[johnwizz]

OK. That makes sense but it is already set to plane.

Thanks!

 

[cowski]

In that case, I'd guess the spline isn't as planar as you think it is.

Was the spline created "locked" to a specific plane (one other than the current view plane)?

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[johnwizz]

Well, things are not always as they seem! It works when I project the spline onto another plane and then extrude it. So I'm guessing you are correct and the spline was actually not created locked into a plane. Thanks for the help!!!