Help with surfaces


I would like to get some professional opinions on this issue: I try to create a smooth transaction between these surfaces but I can’t really get it right:

I have tried different methods with different designs on this surface…

…and it seems to have a quite big effect. What I try to keep is the look from a top view, but otherwise I’m open to small adjustments that would solve this. So far I have recieved either a surface that flattens out too much (attached) or a surface with small bumps. Any ideas?

surfaces_hoffster.3dm (234.1 KB)


I wasn’t really sure which surfaces you were talking about, maybe you could be a little more precise in your post? Also, what do you mean by “smooth”?
However, see if any of these help you: I’ve tried using Sweep2 to create either connecting surface and then both of them with a new guide rail that I’ve created using the Handle curve command.

surfaces_hoffster_v2.3dm (563.8 KB)

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It is possible that there is no single clean surface that can attach to all 4 edges you have specified there.

It looks like some of the surface connections you want to have sharp corners and some you want smooth.

i would worry about getting the smooth transitions right and let the hard corners appear wherever those surfaces intersect
surfacesx.3dm (205.7 KB)

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Thanks for your help! And sorry for my fuzzy description. But yes, you understood correctly and that is the surface I have issues with. You managed to get a better surface than me with your new guide rail, but I still have an issue with this small crease here:

I hade two of those before so this is surely a step forward!

Hi Jim,

Thanks for you support! Awesome surface (!) but I need to try to keep the chamfered design, as an (almost) offset of the outer chamfer (2nd screenshot below).

(3rd sceenshot)I know that this is one reason to the troubles, but I need to keep this silouette dead straight!

Yes, sure, that might be the case! I’ve tried to split it into smaller pieces but with less good result. I also try to understand where I can do minor adjustments to the other surfaces to make life easier for the top surface.

Could you upload a file with just the elements that are strictly needed to be in the final solution? That would help greatly.

Can you also upload a rhino 5 version of the file so I might take a look.

Sure thing! surfaces_hoffster_rhino5.3dm (233.7 KB)

Sure Pietro! I put some of the important curves in the file so one could understand what kind of shape I try to keep.

The curve to the far left needs a radius in the corner, and the middle + the right one has this chamfered shape, The kept surfaces shows the differences in Z/height that I try to accomplish.

The chamfered curves has no radii in the corners in the file, but as you see on the surfaces, the intention is to have them there.

V2_surfaces_hoffster.3dm (91.2 KB)
V2_surfaces_hoffster_RHINO5.3dm (87.5 KB)


Two more questions:

  1. Did I understand correctly that the middle and far right chamfered curves can have a radius?
  2. Is this displacement between the curve and the surface correct?


  1. So the raii will be put where the red rings are. Meaning it wont be sharp corners like the curves.

  2. This surface could potentially be cut where the blue line is. The small “bend” there is a result of me trying to start to accelerate the surface upwards in Z already with this surface. Probably a bad idea. Cut where the blue line is and you should have a flat surface.

Was doing a sweep2 not producing good results?

Here, see if this is better: they might not be as smooth as they could be, but you may need to lose some constraints in your requests.

V2_surfaces_hoffster_v2.3dm (946.4 KB)

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Thank you very much! Your guide rails seems to do the trick pretty good! I will explore more with your file as a base. Thanks a lot!

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