Control point weight not changing anything

HI, fairly new to rhino. I understand and have used control point weight before but now it is not working properly. i try to decrease weight of a control point for a surface but it does not move the actual surface away from the point. It is like it is stuck to

the point no matter what. Do I have the wrong type of surface perhaps?


this is not possible on a surface of degree 1 … it is necessary to have a surface of degree 2 and more to be able to play on the weight

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sorry, i tried to look up what that is but couldn’t find anything that could help me. Can you please explain / show me how to change this? I also need to match the edge of the surface to the corners as pictured. I tried the matchsrf command but I cant select on the corner of the surface.

How did you make that? You seem to have made some kind of mesh, not a NURBS surface.

i don’t think it is a nurbs surface, it is just a simple rectangular plane drawn above the shape and the control points dragged down onto the edge of the base geometry. my main program is solidworks so i’m not well versed in surface editing

Yeah you’ve maybe got a "surface’ but of degree 1. You just need some basic NURBS/rhino training, look at the level 1 and 2 manuals at


thanks for the reply but in this instance I simply don’t have the time to learn more about it, i need this done by Friday. can someone please let me know how they would go about achieving this? just need a surface that i can adjust using weighted control points but that is also fixed by the edge to the base surface.

I have the shape that i want, i used the patch tool on the edge of the base that i wanted, but when moving the control points around it moved the edge off the base. I also want it to be tangent to the vertical surface of the base, pictured with blue line. thanks very much for help in advance

you can use RailRevolve:

after executing the command press F1 to see the help which shows how it works.

Your surface is trimmed. A basic property of NURBS surfaces is the edges on an untrimmed surface are not affected by interior control points. So you need an untrimmed surface with the edges coinciding with the base surface.

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