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Best Fit Surface on a Point Cloud

robert_schartow
robert_schartow Posts: 8 ✭
in Community Support
What is the best way to create a surface using points created in multiple sketches? I am working on a boat hull. The shape is defined by a table of Offsets. These are points measure up from a base, and over from a center plane. Back in the BC days(Before Computers), these points were taken from a scale model created for the desired hull shape. Obviously the resolution in these tables are thus fairly corse. I'm translating a Table of Offsets from1936. Their units are feet- inches-eights. And a "+" or "-" sign to represent a smidgen in one direction or another. So I have 100+ points that now need best fit curvature applied to them. I have attempted to create vertical splines contained by 3d splines and use the FILLED SURFACE feature. When I attempt to use the intermediate vertical splines as guides, it doesn't cooperate. Ideas? Suggestions?
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Answers

  • robert_schartow
    robert_schartow Posts: 8 ✭

  • MichaelPascoe
    MichaelPascoe Posts: 2,943 PRO
    edited March 2021
    Instead of using 3D splines, try creating 2D splines and manually fit them to your vertical rib measurements.

    When creating a 2D spline, it is tempting to use all of the data points. Try to use as few spline points as possible to get a smooth spline.

    For more detailed help, you can make your document public and post the link here.

    RENDERCAD
    rendercad.ai - Photorealistic product rendering.

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  • robert_schartow
    robert_schartow Posts: 8 ✭
    Can't make it public due to copyright restrictions on the data points. But I have created 2d splines on each of the sketch planes to connect the best data point sets. Then created a 3D spline across the top which creates the planksheer. I can create a surface between each section of vertical splines but cannot set the edges to match curvature, so there is not a smooth transition between each. And for some reason I cannot make a larger surface and use the vertical splines a guides. Not sure why. I was able to do it in the past. 

  • MichaelPascoe
    MichaelPascoe Posts: 2,943 PRO
    edited April 2021
    Lofting is very tedious. Every guide has to be perfectly placed. If you are still having trouble with this later, send me a pm and I will sign an nda for you. You could then temporarily add me to the document in order to trouble shoot.

    RENDERCAD
    rendercad.ai - Photorealistic product rendering.

    ▚▞▚▞▚▞▚▞▚
    ________________________________________________________________________
  • EvanReese
    EvanReese Posts: 3,056 PRO
    MichaelPascoe said:
    I will sign an nda for you. You could then temporarily add me to the document in order to trouble shoot.
    Now that's some above-and-beyond forum help, haha.
    Evan Reese
    The Onsherpa | Reach peak Onshape productivity
    www.theonsherpa.com

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