I’m new to Rhino and I have no idea where to go from here. I’m trying to create a surface from a wire frame (not sure what the technical term is) made out of curves, but I’m stuck on how to do it. I tried to do a network surface, but there are 5 sides and it didn’t work. I also tried to break it up into pieces, but the pieces didn’t transition into each other smoothly.
Any and all help would be greatly appreciated.
Bass Neck Help.3dm (159.7 KB)
Split your curves into manageable sections. Then use Surface Edge curves to generate the surfaces.
Thank you for the help.
I just tried using network surface with the surface edges and it worked really well. However, it’s not quite as smooth as your example. It’s nothing some sanding wouldn’t take care of but just out of curiosity is there anything that you did differently?
It is possible to use the NetworkSrf command and select surface edges (not just curves). When a surface edge is selected, in the dialogue you can then select the desired continuity at that edge. If four surface edges are selected, it is possible to make a patch with curvature (G2) continuity on all sides.
Then use Zebra to analyze the curvature light lines (no black-white discontinuities imply G2 continuity).
I gave it some further thought and came up with this. It’s the best way to resolve the surface flow and continuity issues with your design.
I tried to copy this and got lost along the way. Is there any chance you could send me the 3dm file?
@menno Thanks for the tip!
I’d perhaps use sweep2 and checking the retain height or some option like that to get the smooth surface for the arc part.
Between the transition perhaps blendsrf would be best to get smooth transitions.
You can use splitedge command to break up the surface edges to be able to split the surface created by sweep2.
Not that I’m certain it’d create a smooth simple surface as I’m still learning… but I’d start around there to see if it works…
Menno, if the surface has 4 edges so good, but if it has 5, for example, what do you do?
With Rhino is not easy!
In that case, the Patch command could help, but that is more complex to get right.
Certainly, but in this case you can only set a tangent continuity (G1). You never get a smooth continuity (Alias teaches …).
A “Multiblend” tool would be perfect for this kind of situation (for more than four edges). Who knows when it will be developed!
Just search for MultiBlend on this forum to find some interesting discussions
What “case” are you referring to? The use of “Patch”?
The case where you have to put in continuity surfaces with more than four edges: you know the case of the sphere cut by a pentagon? (They just create 5 edges and want to rebuild a continuity with the entire surface). We discussed this in another forum posts
I just made two variants, one with Rhino, one without.
Its not perfect but,
a. haven’t invested so much in it and
b. it shows the problem you having.
I guess its not a matter of matching capability,
but rather an overall problem of your surfaces. You might think of modifying you design, because even if you get a quite satisfying result you get trouble on how they are playing together.
ex.3dm (918.7 KB)
How are you making the extra lines like that? I tried to copy what you are doing but I can’t figure out how you are keeping the lines tangent to the surface.
The left example was made in Rhino without any plugin so you will be able to reproduce this. The right example won’t be possible in Rhino at least without the vsr plugin.
For the Rhino example I often used rail surface with two curves. However you shouldn’t rail on trimboundaries but rather on projected curves. Projected curves are keeping cpcount lower. You can also always try to refit your surface or rebuilding them. The lower your cps count the easier to manipulate them manually. You can also look at the _SetPt function.I also use trim with isocurve with “shrink” on in order to keep the subpatches untrimmed. What also helps is to keep any surface edge transition tangent to the others. Without this is much harder, even impossible to match right. This is why multiblends are crap and will never work good. You also should try fully understand any feature within the match command …