how to do the job for a fair and best bulbous bow shape?

Discussion in 'Software' started by zeroname, Dec 30, 2009.

  1. zeroname
    Joined: Oct 2008
    Posts: 276
    Likes: 5, Points: 0, Legacy Rep: 90
    Location: Europe

    zeroname Naval Architect

    hello guys,

    i am in a problem which is very common if any one want to do 3d hull shape with bulbous bow from an existing lines plan. i am trying it do in rhino. but i get it hard to produce a fair shape. many people say use loft , or use networksurf . or etc.. but dont see who did it by himself rather than giving theory.
    i will be happy to get some help if any one show me a way to make the good shape from this lines by doing it as an example ;)

    Thanks much..
    still learning :)
     

    Attached Files:

    • bow.3dm
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  2. bhnautika
    Joined: Feb 2006
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    Location: australia

    bhnautika Senior Member

    Zeroname using just sections for this surface won’t give you enough information, there is too many gaps to fill in around the bow area for where the edge of the surface is. Sometimes a mix of waterlines and sections gives you a closer match. Also dividing the surface into different parts rather than one piece can make it easier. Because your line drawing of the sections is made up of a lot of control points you need to use the “rebuild with” function in the loft options to reduce the number of points to just enough to get your shape. I used some of these methods to do a quick down and dirty shot at it.
     

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  3. zeroname
    Joined: Oct 2008
    Posts: 276
    Likes: 5, Points: 0, Legacy Rep: 90
    Location: Europe

    zeroname Naval Architect

    thanks .. and nice to see ..
    then u did following by rebuild command to reduce control point and then ...
    if u kindly share the sequence [ if u dont mind !] will be a good support. as i am learning ...

    if u can kindly pm me the 3dm , so that i can analyze and modify it more ...

    thanks
     

  4. bhnautika
    Joined: Feb 2006
    Posts: 849
    Likes: 56, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    Zeroname in the loft > rebuild, you can put in the number of control points for the surface. Play around with the number using the preview button until you get the surface accuracy that you want. The most important thing with loft is always pick the lines from the same end (say the sheer line end in this case). Here is my file, which is not perfect as it has gaps between surfaces. The trouble with creating surfaces from lines using loft is you have trouble with the edges of the surface between the sections, as they end up being the side edge when it should have been an end edge.
     

    Attached Files:

    • bow3.3dm
      bow3.3dm
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