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mattedmonds

Nurbz surface help needed - Please!

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I've never been a nurbz guy, but trying really hard to make this work. I have two defined edge profiles that came from someone else's Rhino model. In the first import it came in as a finely segmented polyline, not a smooth curve. This resulted in a very densely subdivided nurbz surface on my first try. It's interpolation of how to connect the profiles was therefore not what I was looking for.

Here's are the elements used and the resulting shape.

image.thumb.png.fac902b5cf7449e52a21718e99d49a27.png image.png.22460ae1b17765c81c76c456ee04be53.png

Here are my comments on the resulting geometry... (just noticed the misspelling of fishtail!)

image.png.8b237530cdeb9127629b2b63a3945fe3.png

 

I then reimported the file from Rhino using a different format at now have a couple different types of profiles. The one on the left is a plain smooth object, the one on the right is a trimmed Nurbz surface. Not sure why this happened.

image.thumb.png.8dff12d359b2529c1f75feba6a0d1309.pngimage.thumb.png.57184f3240084b4607109d57009226a2.png 

When I attempt to use these object to generate a new Nurbz U/V surface it doesn't accept the source objects as complete elements... only individual segments, and then fails to generate the shape if I select each curve and segment individually.

My hope is to generate a new nurbz surface from these objects that is much simpler that my first attempt.... so that i can then subdivide it manually and adjust the curvatures to achieve the fishtail transition from the double ridge on the edge of the left side of the panel to the concave valley on the right side of the panel. As you can imagine, goal is for the curved surfaces of each panel to be tangent to that on the adjacent panel.

Also, its important to understand that the curved transition path is an s-curve in both plan and front elevation.

Question... does the s-shaped path curve need to terminate at a point on nurbz surface on the left for the N-UV tool to work?

Really appreciate any help or suggestions.

Thanks.

Matt.

FZ 8.6 Pro, Windows 10

 

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I suggest copy-pasting just the left side flat segments/face(as a smooth object),  into a new project. Then move-copy it to the right side position. Next treat just the part which you want changed on the right side,  by first using the C-Recon Tool to change it to a smooth  3º curve, and then switch to Pick Tool and make sure Inspector has "Show Controls" indicated.  Next select all the points between concave ends, and Independent-Scale them to the level of protrusion you want in the final result. Immediately save this result, (as it's own project name), before proceeding further. Next reshape the whole segment to conform with the concave sample you would have also snapped into place before this step.

This procedure assures that some degree of ridge detail will exist on the right side after you use the N-Loft Tool, and you can use N-Edit to refine the look in Shaded Work View.

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After more thought: It might be possible to make the NURBS surface with both ends identical, and then use Independent Scale Tool on the concave end.

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Super helpful Bo. I'm going to start with your second approach to see if that works. If I understand you correctly, the independent scale tool is to move the controls on the right side into alignment with the simple concave right edge profile?

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Try exporting out of rhino using the .stp format. Especially for solids stp is usually the best way to go and the surfaces will be identical to the ones in rhino.

If not, you can try cleaning up the curves and re-lofting. Derive the two curved segments using the Derive Segments tool and then, on the one that is more complex, use the Curve Reconstruct tool.  Adjust the number of control points and the tolerance until you get a close enough result.  you can get a visible indication of how much the curve is different that the original by selecting the Show Deviation option and zooming in. Once you have the first curve cleaned up, use the identical settings on the other curve and then loft between them.  Note that the new surface will be very slightly different than the original but if it is not critical this will clean it up nicely.  Also, be aware that if this part is connected to other curved parts you may need to be aware of the continuity of the rebuilt surface to the adjacent parts.

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On 2/9/2021 at 7:19 PM, mattedmonds said:

Super helpful Bo. I'm going to start with your second approach to see if that works. If I understand you correctly, the independent scale tool is to move the controls on the right side into alignment with the simple concave right edge profile?

Yes, because beginning with two identical curves, which are lofted into one surface, assures consistency from left to right, providing the subsequent editing, does snap to  a plane which is based on the closed curve which is being edited.

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If I'd you I'd rather redraw those profiles in order to get nice clean model. Seems like the original profiles are quite simple.

Yet you should be ready not to be 100% presize.

 All those import things not always work in FormZ

NURBS.JPG

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