I would like, please, to know, how to do well what i tried here!
Step 1 and 2: I designed curves, in order to have a surface, using “Network srf”
Step 3: As i wanted to have a closed polysurface, i tried to use “Offset Srf”, 1mm. But, here, i have a big problem, and i don’t know why: i can’t have a closed polysurface. It is an opened polysurface. I don’t know why. I think, maybe, it could be because it seems i have a hole a the center of the initial surface i created using “Network Srf”. But really, i don’t know why.
Step 4: I tried to resolve this, using “Blend Srf”, first, exploding all the surfaces, and, then, taking a lot of time trying to recreate the surfaces with “Blend Srf”. At the end, this is a closed polysurface, but, really, i would like, please, to understand, why it seems the origin of the problem is using “Network Srf” with the curves i created.
Could you please help me?
I join here my Rhino file
Thanks so much! Network Srf Forum.3dm (1.4 MB)
The problem originates with the singularity in each surface at the top where the surface has a zero length side. If you offset one surface rather than the polysurface you can see the problem. (Explode the polysurface, Hide one surface, OffsetSrf the other surface.)
you have one curve duplicated, i am not sure if that is a big issue since you seemed to have made NetworkSrf out of 2 parts anyway which leads to the first issue seen on the 2nd image here
now use NetworkSrf, the result is much cleaner, is still has a singularity then. though its better manageable, loft with the 3 vertical curves would also work, you are almost exactly in the curvature then, though it will still create a singularity.
Some attempt using trimmed corner approach. I think this can be much better with better refitting care of the curves, but I only had 15 minutes for this over lunch. It is water tight as a polysurface, and does offset to 1 mm. No singularities. You can see the GEC results too. Centreline of surface leaves some to be desired at 0.85 degrees of tangency, I think it can get down to 0.2 or less with a bit of work. But I don’t know what your tolerance is, or design intent.
two more options attached. I extended one of the curves, copied it and made a loft through the three curves (then trimmed the result)
The other option is XNurbs Network Srf Forum_SG.3dm (1.4 MB)
Hi David, thanks so much! I am not using a lot this command “Show edges”, with the option “Naked edges” selected. I know i should learn it, because it is very useful.
I have to learn this! Thnaks so much!
Hi Encephalon, thanks so much for your answer. Yes, i have one curve duplicated, and then, i used Network Surf from the 2 parts, and i did not want to have what i have here, in this step. I only didn’t know how to do this surface, using networkSurface, that 's why i duplicated the curves, and of course, i have a strange thing. I have sometimes problems using Network Surf, that is a very powerful command, but i see i don’t know very well how to use it in a good way.
You explain me that you would join these curves into one single curve and then make Network Surf. You would join the two yellow curves? And how, please? I think i don’t understand well, i beg your pardon
Thanks so much for your help!
Hi David, thanks so much. I don’t know very well how to use Trimmed corner. Can you, please, explain me this, in few words? You mean that i have to rebuild the curves, and then, after, using Trimer corner?
Thanks so much!
Thanks so much for your help! I am not using a lot “loft”, so i have to understand this command. Too, the “extend” command i have to find. And, Trim command, too.
I don’t know at all the new function of Rhino, that is Xnurbs. I have to discover it.
Thanks so much for your precious help!
