how to draw bulbous bow using rhino??

[tjrrong]

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

Pls provide to me ..

thanks

[CGN]

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.

[Polarity]

Originally Posted by tjrrong

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

Pls provide to me ..

thanks

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.

http://boatdesign.net/forums/showthread.php?t=1401 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
Loft.
mirror
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. http://www.boatdesign.net/gallery/sh...500&ppuser=173

Hope that helps!

Paul

[cestes]

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 http://www.emarinetraining.com 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 emarinetraining.com

Regards,
Cliff W Estes
BaseLine Technology
Rhino reseller and user.

[mdburges]

Originally Posted by Polarity

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.

http://boatdesign.net/forums/showthread.php?t=1401 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
Loft.
mirror
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. http://www.boatdesign.net/gallery/sh...500&ppuser=173

Hope that helps!

Paul

Paul,

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?

Thanks,

Mike

[mdburges]

Originally Posted by mdburges

Paul,

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?

Thanks,

Mike

I think I figured it out, but thanks anyways.

Mike