Rapid Surface snap to facet body.

[cobaltred]

Hi again, NX 9, Rapid surface command I select the facet body, check draw on facet body, and select under attachment, facet body. Ready to draw my first or four curves to define patch.
Question one. On the object snaps bar by default I have endpoints, point on facet and point on face selected, I can click my points for the first curve onto the facet body and hit the finish flag to begin my second of four curves on the facet body, The first point of the second curve is fine because it snaps to the endpoint of the first curve but when I place the second curve it snaps wildly all over the place on the mesh. The only way I have been able to go forward is to turn off the point on facet snap and it seems to work fine. Then I hit the flag to finish the second curve and the object snap bar defaults back to the
default and again I have to turn off the point on facet for it to work. I thought I had this command mastered in 8.5 and I am wondering if something has changed or is there a way to adjust the default snaps or
maybe someone could tell me why the point on facet would not be the right choice instead point on face works it makes no sense to me. I should be able to turn off point on face and turn on point on facet.
In fact to do what I want I should only have to turn on point on facet and endpoint to do my work in that command so how can the default snaps be set up that way.
Also related to this command: I noticed the first curve on facet body acts like straight line segments not a spline on surface, the second and forward curves act like I would expect a spline on facet body.
If I edit the points though it seems to convert to a spline I do not remember this behavior in 8.5.

Thanks, Buddy.

 

[Toost]

1) The button "Finish flag" is green = Middlemouse button ( all green buttons has this meaning)
2) the new (?) option "point on facet" body is really "Point on facet vertex", - i.e the actual point in the cloud where the "point on face" will also select intermediate positions. ( Between the points are the facets which are planar, = linear interpolation of the points.) Compare this to a circle where a number of points have been placed on the arc. between these points are chords (lines) then "points on face" will allow snaps to these chords.) Depending on the density of the cloud this approximation can be either ok or not.
3) i cannot say anything about the interaction or if it flickers etc. You need to speak to GTAC on this.
4) The curves will always be splines.- They have to have to be able to follow an eventual curvature. in the bottom of the dialog you can control the degree and number of segments that each spline will have as soon as "finished", in my session the default is degree 3 and 6 segments. if you only pick 2 points and then "Accept points", NX will between these "drop" as many points needed to create the degree 3/ 6 segment curve.

Regards,
Tomas