how to draw bulbous bow using rhino??

Discussion in 'Software' started by tjrrong, Aug 2, 2004.

  1. tjrrong
    Joined: Jul 2004
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Malaysia

    tjrrong New Member

    any members have experinece drawing bulbous bow using rhino.....

    Pls provide to me ..

  2. CGN
    Joined: Jan 2003
    Posts: 547
    Likes: 9, Points: 18, Legacy Rep: 138
    Location: MX

    CGN Senior Member

    Hi, what i do is just "push and pull" using the vertexes to shape the bulb, i will say that usually your bulb will be faired into the hull, as a part of the hull, so i use one surface with as many controls points on it so i can shape it, in the way i want.

    this is if i'm creating the hull form scratch.
  3. Polarity
    Joined: Dec 2001
    Posts: 480
    Likes: 7, Points: 0, Legacy Rep: 148
    Location: UK

    Polarity Senior Member

    Sorry did not see you had posted here, I replied to your PM
    But for anyone else interested here is a copy

    First you have to realise I can only tell you how to draw it simply in rhino.. I'm not a designer!

    If you have not already check out my tutorial on drawing a quick boat hull. should take you right there...

    Then in profile
    Draw the bow line and the profile of the bulb using control point curve - make a smooth transition
    put a point at the end of the bulb
    Plan view
    draw the half plan shape of the bulb - start at the point end just beyond where you think it will meet the hull surface
    see turorial instructions for removing the "kink" where the shapes join.
    Offer up to the 3d hull surface and either trim or boolean union
    Will post a pic or two in my gallery for you.

    Hope that helps!

  4. cestes
    Joined: Apr 2002
    Posts: 23
    Likes: 1, Points: 0, Legacy Rep: 60
    Location: Redmond, WA

    cestes Junior Member

    The short answer is that you create the hull, then create the bulb, trim each back some distance and blend between the two.

    This will create a surface, which has curvature continuity (g2) at each edge.

    The long answer requires many paragraphs and illustrations, but is possible.

    We will be doing a Rhino Marine Modeling class online at starting in September. In that class, it will be possible to delve deeply into this question.

    The class will take six weeks and will involve learning creating and fairing curves and surfaces. In week 3 we will create a hard-chine model. Then in Week 4, a molded hull sailboat.

    Finally, each student will spend the last two weeks doing a self-directed project with supervision from the instructor.

    Check it out at

    Cliff W Estes
    BaseLine Technology
    Rhino reseller and user.
  5. mdburges
    Joined: Feb 2005
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Vancouver, BC

    mdburges New Member


    I'm and undergrad student at UBC and I'm doing a project on the design of a bulbous bow for a 'thin ship'. Anyways, I've followed your instruction, but I'm having trouble at the loft stage. Whenever I loft, it seems to give me an 'inside out' bulb. Do you have any suggestions?



  6. mdburges
    Joined: Feb 2005
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Vancouver, BC

    mdburges New Member

    I think I figured it out, but thanks anyways.

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.