Absolutely new to Rhino - modifying imported DXF

Discussion in 'Software' started by rwatson, May 15, 2012.

  1. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    If there is anyone out there with a bit of time on their hands, you may be able to advise a novice.

    I have imported a DXF file into Rhino 5, that wont render.

    I expect it is due to unresolved surfaces - lines that don't form a proper surface.

    I tried the 'loft' command and got the message
    "Unable to loft - select either open or closed curves, but not both."

    Any explanation of that message would be very useful
  2. ldigas
    Joined: Feb 2011
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    ldigas Senior Member

    In your .dxf file, did you import curves or surfaces? If there are only curves, then it won't render properly - has nothing to render.

    Loft command is telling you to use either open curves, or closed curves, but not to mix them. Closed curves are the ones that don't have edge points ... points where the curve "ends". An airfoil would be for example, a closed curve.

    Can't say much more based on the given info ...
  3. daiquiri
    Joined: May 2004
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    daiquiri Engineering and Design

    If you are using Freeship or Delftship to create the dxf file, then it will contain only a mesh of curves, with no surfaces. You have to form the surfaces within Rhino before rendering, by using the Loft or similar commands.

    An easier solution would imho be to export the surfaces as IGES file from Free(Delft)ship ad then import it into Rhino. They will be immediately visible. Before continuing the work with the imported hull model, I'd advise you to check if there are visible gaps between the edges (you can be sure there are ;) ) and to eventually join them with the JoinEdge command. See this manual for a more detailed explanation: http://www.rhino3d.com/tutorials/troubleshootiges-a4.pdf

    As Idigas has noted, you have tried to loft a set of curves which contain both open and closed ones. A typical case might be the selection of transom (imported as a closed curve) and frames (which are open). The solution, in that case, is to open the transom curve by cutting the deck and midship segments of the polyline, and transforming the transom into a frame-like curve.
  4. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    Thanks for that info. As Daiquiri guessed, i was exporting files from Freeship, and as Idagas sugested, when I chose another type of output, it rendered and viewed shaded fine.

    I will try that IGES technique today as well. I will also read up on what the difference is between curves and surfaces - new concepts to get to grips with.

    Many thanks for such helpful advice - very much appreciated.
  5. RThompson
    Joined: Nov 2004
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    RThompson Senior Member

    I don't if you've done them or not-
    As an introduction to working in rhino it is well worth doing the three tutorials listed under 'help'. I think there is a torch and rubber duck and something else.
    A couple of hours playing round in there is good value for anyone new to rhino. true story! :)

  6. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

    A second to RThompson's suggestion that you take time to go through the tutorials. In Rhino 5 the basic tutorials can be accessed using the drop down Help menu by selecting Learn Rhino. Start with the three short tutorials under Getting Started. Next would be the Rhino 4.0 Level I and II Training which can be downloaded by the link under Tutorials on the Web or http://www.rhino3d.com/tutorials.htm
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