Orientation of prep frames and surface on 3D curve

Hello, Im quite new to grasshopper and im trying to paramatrize cross section, orient it along random 3D curve and sweep it along. So the paramatrization and sweeping wasnt problem, but I have issue with prep frames and surfaces that i place to them. Im attaching Rhino file and grasshopper file containing two scripts that I use to orient planes to curve. (upper and lower one).

First issue is a common one that was asked many times before. When I use prep frames, some of them have randomly changed axis orientation - thats upper script. I used Align Plane to unite them in lower one, but now frames are rotated along curve X axis - I need them in parallel to world XY as it was in upper script and I cant find a way how get it this way with Align Plane used.

Second issue and worse for me, is with 3D curve and usage of prep frames. Prep frames creates planes perdicular to curve, but I need to rotate planes or surfaces on them to always point to global Z direction. There is a picture what Im trying to do at prep frame of 3D curve with elevation. Is there any way how to do it?

  • Green line represent state i need to get.

Prep_frames.gh (14.6 KB)
Rhino_Crossection.3dm (68.2 KB)

Thanks a lot for help.

It sounds weird but if you want vertical planes on the curve, it’s almost easier to use the Horizontal Frame component.

vertical_frames.gh (5.4 KB)


Thats exactly what I needed. Thank you very much.

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Thanks. If you’re happy, please click the solution button.

perp frames… perpendicular…