Whenever I try to move the control points, the 3 sided surfaces deform

Rhino
1

Hi everyone,

Surfaces made by the command _SrfPt.

Is there a way to modify from control points without causing unwanted deformation?

Any advice on the best workflow for this would be appreciated.

brvdln (Brv) 2

3

Thanks for yor interest but I need a solution for the surfaces made by command _SrfPt.

XXX
XXX883Ă—545 31.3 KB

4

Triangular surfaces (3 sides) are trimmed surfaces, each with a fourth control point off the surface.

An alternative would be to create lines between the sets of three points, and then use EdgeSrf to create the surfaces. Each of those surfaces would have one zero length side with two stacked control points, which can be manipulated as a single control point.

5

Thank you.

6

try modifying the points after SolidPtOn command

7

What a great command…! Thanks a lot for your help.

8

this is the reason - as @davidcockey pointed out:

image
image1787Ă—1304 105 KB

left: trimmed, right untrimmed
back: point moved
front: initial triangles

trimmed - left:

_srfPt 3 clicks resulting in a trimmed Surface

untrimmed / collapsed edge right:

_srfPt Pause Pause Pause r0,0,0 or clicked the last point twice resulting in a untrimmed surface with a collapsed / zero-length edge. Collapsed edges might be problematic for some workflows. but for the edit you are after they are the way to go. (no need to draw lines)
(Edit: another way to draw a triangle: loft to line that share one corner point)

cheers - tom