What are these points called?

rhino
controlpoints
rhino5

#1

Hi, guys.
What are these points called? It looks different from control points. Appears around the boundary. Seems to have the information of the slope at the end of geometry.


In scripts, I can access control points by rs.ObjectGripLocation. Are there any command to access those points too?
Thanks.


(Pascal Golay) #2

Hi Ayoshi - as far as I can see those are regular surface control points.

-Pascal


#3

Hi Pascal.
I can’t find them in normal control point data. They are part of control point but not stored in the same place.
And when I’m using grasshopper to get the control points’ data, they are not included either.


(Pascal Golay) #4

Hi Ayoshi - are you dealing with meshes or surfaces? In your first image, it looks like you have a surface, and in the second one a different surface - degree 1 in one direction, perhaps? At any rate, surface points are not the same as mesh vertices…

-Pascal


#5

Aren’t those tancency handles? I only see those in TSplines surfaces normally…


#6

Thank you for the reply, Pascal.
It is T-spline surface in first pic, and box mode in second pic. I should use T-spline component to show you, sorry.


When i select all control points in Rhino it was 2332 points, but in grasshopper it was 2243.
Now i realize what vertices or points in the grasshopper component output doesn’t mean control points. Thank you.
I want to use ghpython in grasshopper to build two component, one is to extrude t-spline, the other is retopo(projection) tool which can apply on whole geometry and set the error limit. So only Rhinoscript can help me access and edit the control point data, is that right?


#7

Hi cairn.
Yes this is Tsplines.
Tangency handles! Thank you for telling the name of it.