I’m fairly new to Rhino so go easy on me. I do Marine Decking with our 3d scanner and import into Rhino to poly line the shapes. However sometimes the surface is not flat so I cannot poly line over a rounded surface. My question is there a way to “unfold” or draw on a curved surface and unfold to a 2d?
You can achieve it with SnapeToMeshObject + Curve + Pull to achieve it, fyi.
Are you importing a mesh or a NURBS surface?
If a mesh use PolylineOnMesh to draw a polyline on the mesh.
If a NURBS surface there are several options:
ExtractRenderMesh or ExtractAnalysisMesh to obtain a mesh. Use PolylineOnMesh to draw a polyline on the mesh.
Use CurveOnSurface to draw a curve on surface. If you need “straight” line segments then use CurveOnSurface to draw each segment separately on the surface, with the End Osnap turned on to start a new segment at the end of the previous segment. Join to join the segments together.
To flatten a surface you can use UnrollSrf if the surface is developable or close enough to developable. Otherwise you can use Smash or Squish to flatten the surface but there will be some distortion. UnrollSrf, Smash and Squish allow selection of points and curves on the surface to be unrolled along with the surface.
Squish also works with meshes.
Are you trying to unroll a surface or a polysurface, or a mesh? Based on the image it appears to be a mesh. UnrollSrf only works on surfaces and poly surfaces.
It’s a mesh trying to draw a poly line over. So when I draw a poly in perspective mode I need to unfold that so it’s 2d in top view.
