A one zillion dollar question...SOLID 3d hull from CAD

[Stefano Salesi]

Hy to you all...i need to model a SOLID 3d hull in Autocad 2007. it has to be a solid, and not a surface or a mesh...i have all the correct drawings and hull lines...but...what key can I use for making the solid?? tried loft and sweep with no luck...any hints?

[Cadman]

Loft is the correct command. But your lines need to be closed in order to form a solid.

Notice each hull line included the deck line (with camber) and is closed by including the centerline. This way a solid can be formed when the command completes. You need to also select the solid option from the Loft dialog. Smooth or rules surfaces with give you different effects. Ruled will be somewhat jerky, while ruled usually blends the surfaces together in a more realistic way.

[bigtodd]

One other thing is you may be trying to do too much at one time. Remember that a solid model is actually a surface model that has been joined together to leave no holes or gaps. Solid functions are actually creating surfaces and capping the ends for you automatically. It does what you tell it to do. When it does not give you the result you expect then you did not give it enough controls to give you what you want.

If the commands you are using do not give you what you want you will have to try to create things in smaller steps. You will have to work with surfaces individually and then join or stitch them all back together again at the end to form the solid. It takes a little longer but you get what you want.

When I teach advanced surfacing in CAD I use the old tale. "How do you eat an elephant? One bite at a time."

Just make sure you are taking to big of a bite when you are trying to model something.

Todd

[Stefano Salesi]

thanks a lot! i will try immediately! very useful answers the both you gave me! thanks!

[Cadman]

Also like Todd says don't try to do too much at once. Do your lofts in small sections and then join (union) them later. AutoCAD will tend to get overwhelmed if presented with too many lines to loft. So unless you have a full blown supercomputer workstation, I would do it a little at a time.

Oh and post some pics so we can see how you are doing.

[Stefano Salesi]

luckily enough i have a full blown supercomputer...i'm an architectural student and i work with autocad since 6 years...but I always had problems in making 3d hulls...even if i'm pretty trained in 3d building modeling and in rendering......

thanks again, i will post the result of the experiment as soon as i can!