Issue in Network Surface: Surface with hole

Rhino
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1

Hi,

I have this Surface which I created with Network Surface. Everything seems normal.

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And then I tried Offseting it using OffsetSrf.
And I noticed that there is a hole in the middle of the offset result surface.

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Why is this happening? How do I get a smooth clean surface just like the original one?
Is this something to do with the curve from which I created the NetworkSrf?

I have attached a 3DM file containing the original curves, original Network Surface, and the offset result (with holes).

network srf 1.3dm (5.4 MB)

Thanks a lot!

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normal direction
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The blue arrows show the direction of the normals.

1 Like
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A patch is probably an easier route for this surface:

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2 Likes
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Ah I see. An interesting explanation. Thanks!
Although, I still wonder what’s the best way to have continuous curve in my situation..

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Thanks Gijs! This is one smooth surface.
But, then…I noticed that with patch, it loses the “radial topology” that I want to use for paneling process with Grasshopper :sweat_smile:

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Sorry I forgot to mention that hehe.

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I’d use loft in that case. Make a copy of the curve, scale it in z to the height of the point, then scale it in XY and loose loft it:

loft.3dm (262.7 KB)

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7

How would you create a surface using Loft from the original network of curves - ignore some of the curves?

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8

The root cause is the shape of the input curves. Upload a file with the input curves if you want assistance with how to fix the curves.

To make the current surface generally smooth with tangent continuity at the center.

Turn on control points for the surface

SurfaceThrough Pt the center control points using first set of control points near the center.

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ExtendSrf the edges of the created plane to make it larger.

Pull the center control points using first set of control points near the center onto the plane.

The result should be smooth with tangent continuity at the center. It may deviate from the input curves near the center.

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Not use them at all. It’s an assumption that the input curves are arbitrary and the goal is to have a clean surface rather than an exact match to the sectional curves. The OP can correct me if that assumption is wrong :slight_smile:

10

Thanks for the input guys!

I ended up using Gijs recommendation of “Patch Surface”.
Funny thing is that, I ended up using Patch Surface as the “target projection surface” at the end of my script, BUT STILL using Loft (with holes) to get the topology and the structure of the surface.

And thanks rhinouser141 and David Cockey for the input on the curves. I am going to use it also if I have more time to process the curves better.

All inputs are very good! But I can only put one as solution. So, I am going to choose Gijs Patch as solution. Thanks a lot. Sorry for the late reply