How do I deal with this transition? (Rhino)

Discussion in 'Software' started by adt2, Jan 19, 2011.

  1. adt2
    Joined: Sep 2009
    Posts: 100
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    Location: Magnolia, Texas

    adt2 Senior Member

    I'm a new-ish Rhino user, and I'm having a little trouble with a hull side-to-transom detail (see the attached image). I figured out how to use Trim to trim the funky triangle of hull side that extends onto the swim platform area, and I'm assuming I can use the same function to trim the curved transom flush with the hull side.

    What I can't figure out is how to deal with the missing triangle at the aft edge of the hull side, below the swim platform. Is there a way to extend the hull side surface to the lower transom edge? Or should I add a point along the sheer, way aft of the transom, to extend the hull side surface and then trim it at both the upper and lower transoms?

    Thanks in advance for any assistance you can offer.

    Attached Files:

    Last edited: Jan 19, 2011
  2. ACuttle
    Joined: Aug 2008
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    Location: UK

    ACuttle Marine Design Engineer

    Before you trim the surface out above the swim platform, select the sloping vertical edge of your side surface and use the 'extend surface' command (I don't recall the menu of the top of my head but it's just off one of the primary tool bars). Extend it out by 500mm or so then trim it back onto the swim-platform and the transom.

    You can extend trimmed surfaces but it doesn't do such a nice job, your better off to extend the surface untrimmed and then trim back wherever needed.

    Just shout if that doesn't makesense.

    I've just checked, it's on the 'surface tools' toolbar - fairly predictably.
  3. adt2
    Joined: Sep 2009
    Posts: 100
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    Location: Magnolia, Texas

    adt2 Senior Member

    That did it - thanks.

    I think what threw me off on that command was the Command Line prompt ("Extension factor <1.00>:"). WTF is that? Why not have that prompt read "Extension length <1.00">:" or something similar?

    Anyhow, thanks for the help.

  4. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    The "extension factor" input of the "extendsrf" command is one of the more mysterious elements of Rhino. It isn't a simple distance and it isn't a simple proportion of the surface size. It also isn't linear. An extension factor of 10 doesn't necessarially result in an extension 10 times longer than an extension factor of 1.

    I generally start with 1 and if the extension is the wrong length by a considerable amount I undo and try with a different extension factor.
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