Hi all,
I have stunbled upon a nice design (author is Benjamin Cann, on i-materialise), and I am wondering how it can be made with Rhino.
The problem is not the shape, but the way a wire like that can be bended around a surface/polysurface…
I think flow along surface would not make it since there are a lot fo curvature issued in this model…
Any suggestion?
Draw a curve on rhino shape and use continue curve command keep drawing… So far I can think of… For the curve degree, it should be 5?
Another option which may give some good results would be to go to an orthographic view, and project curves onto your surface. You then could blend the curves that were projected onto the surface. And use pull to pull that blended curve tighter to the formation of the surface if need be.
Projected curves from Front view.
Blended curve, then Pulled to surface and joined as one polyline.
This seems to be interesting…I have done something similarnbut without pulling them back
probably this wont help much, but I think you can easily achieve that in a couple of method depending on how detail you want it to be =
- visualization only [less control of the “ribbon” geometry] just apply material with opacity map and normal map that you find similar to that. hit render and it is going to look fine if its not a close up shot
-
NURBS workflow [perfect control for curvature, however you will have to save ur original curve and rebuilding the surface quite alot] = use Curve on Surface and freehand the ribbon one by one (dont need to worry about the overlapping part at first because later on u can just offset normal direction once you are done (curve on surface has the advantage on getting the normal direction of the underlying surface, useful when u want some part to overlap the others)
3. Multiple software [expensive but geometry will be easy to tweak] = export the base geometry from rhino to a poly based software with a gool retopology tool (Zbrush, Maya, 3dsmax or u can use T-spline for Rhino. it can do the same.)
use retopology and start drawing the “ribbon” around the geometry, once you are done, convert poly to NURBS and export it back to rhino, and apply pipe command for that groove detail.
I found the 3rd method produce the fastest result, however you will have to keep the edge loop tidy so it would be easy to convert it back to NURBS =
here is the process =
retopo ribbon after importing geometry tweaked NURBS from RHino. retopo until you are satisfied with the design, dont need to worry about the groove detail at the moment. after that export the model back to rhino, convert or Rebuild poly to NURBS and then use pipe command or Sweep command. (sweep command allows you to have customized profile. however in this case it works in both command.
I use sweep with circle profile in RHino… if you spend more time on the retopo part, you will get cleaner and better curvature. (I use curve degree 2 when converting it to NURBS so the ribbon doesnt look very smooth. u can use higher degree for smoother curvature if u want.
hope that helps.
(note = the ribbon I made was slightly “above” the underlying geometry because I accidentally turned of retopo snap while inserting edgeloops. I Didnt save the file so I just offset the original geometry back. make sure u keep retopo snap until the very end to avoid this.)
Great! I suspected that other tools were nearly the only choice to make it quickly. I never used retopology…I’ll check it. Thank you all guys.
Or you may try _Sketch–>Onsurface command.
T-spline also has retopo, but only limited to retopo snap only., however for this type of model you dont need robust retopo tool, a simple one in Tspline will do the job.
I often use retopo to restructure the model because normally I would end up with extremely bad mesh/nurbs topology after tweaking and moving vertex / ctrpoint around during design phase. retopo can be a good friend to tidy up your model especially for better rendering or for clean starting srf before adding complexity in Grasshopper.
note - retopo works best when your base model is either NURBS or dense Mesh.
happy modelling 
Thank you all guys, I have to spend some on retopology…I guess!