Planer Surface Question


#1

I guess my understanding of NURBS isn’t as good as I thought. So how do you have a surface that has a degree on 1 in the U and V direction, but isn’t planer? If I run the command IsPlaneSurface() in python it returns false.

I can see where a surface could have a degree of 1 in one direction but not the other not being planer, like a helix. My thinking is that if it’s a staight line in both direction it would have to be planer. What am I missing?


(Pascal Golay) #2

Hi Dennis- if you make a surface using Plane, then turn on points and lift two opposite-corner points up out of plane, you’ll see…

-Pascal


(Rajaa Issa) #3

For more details about NURBS structure, I recommend you check the Essential Mathematics:
http://www.rhino3d.com/download/rhino/5.0/EssentialMathematicsThirdEdition/


#4

Duh a hyperbolic paraboloid.

Also realized i was using the wrong test function. I should I have used IsSurfacePlaner(). Man I need to go back to bed.