arbitrary solid modelling?!?!

[InfiniteEngineer]

Hello

i wonder how its possible to tell autocad (2008) to turn a closed region in the 3d space into a solid object, Providing the region is surrounded by curved surfaces of different shapes.

many thanks

 

[TCARPENTER1]

Hi InfiniteEngineer,

I'm not sure I understand what you're asking, but if you have a closed region, and it's truly a region object, all you have to do is extrude it, and it will be a solid.

HTH
Todd

 

[InfiniteEngineer]

Hi TCARPENTER1

many thanks for your reply. Sadly enough, autocad 2008 only extrodes plan surfaces, i.e. curved surfaces or surfaces that result due to rotating a curve about an axis cannot be extrode :-(

I will simplify my question by this example (but this example is so simple and can be done other ways!)

say you have a "dome" that resulted due to rotating a sinusoidal half-wave aroud its axis. the base line of the dome meets the base line of another dome made by rotating an ellipse arc.

the space which is confined between the two domes cant be turned into a solid!! i couldnt find such a command :-(

is you need more detail i will upload the drawing

 

[TCARPENTER1]

Hi InfiniteEngineer,

I think I see your issue. What you would need to do is join the two solids together from your example, (and they do have to be solids), and then use the section command to generate a planar region to extrude.

HTH
Todd

 

[InfiniteEngineer]

HI TCARPENTER1

Autocad 2008 doesnt change any surface ito a solid im afraid :-( which makes things more comlicated!

Its possible to change a surface into a solid and back to surface ONLY in the case of [ lines, polylines, circles, cirlce arcs & Splines ] as those elements can produse a surface by the property (Thickness) and that surface can be turned into a solid and vice versa.

All other kinds of surfaces cant be turned into a solid on its own (a solid shell) and i dont know why the hell is that :-(

any way, here is an attachment about the surfaces im talking about u can play with it and please let me know if u can discover any thing good in terms of turning a surface-confined 3D region into a solid object ;-)

i solved the problen in a veryyy long turn-around its all explained in the file!

Again PLEASE let me know if you mannage to turn the confined space into a solid

many thanks

 

[TCARPENTER1]

Hi InfiniteEngineer,

I'm afraid about the only thing you can do is to give M2S.lsp a try. It will convert open meshes to solids but I'm not sure it's going to quite do what you want. I'm afraid AutoCAD doesn't do much with surfaces at this point.

Sorry if that's no help!
Todd

 

[mcgyvr]

Why would anyone use Autocad for surfaces/solids/3d work..
Its like using an etch-a-sketch to do drafting work.

 

[InfiniteEngineer]

dear mcgyvr
i was expecting some useful suggestion related to the topic !! you didnt even recommend an alternative to Autocad!

i agree that autocad lacks lots of the necessary operations that can be done upon solids and surfaces. :-(

any way it works quite well but with loads of tricks, and that is the thing i hate! i prefer simple stuff.

so if you recommend any better alternative please name it

 

[mcgyvr]

Autodesk Inventor for 3d/solid models/surfacing work.
(targeted at mechanical designs in the 3d world)
You can get a 30 day trial..
Autodesk Autocad for 2d work.

If you need to model parts with surfaces and in 3d then Inventor is a MUCH better solution.
And a fairly easy learning curve.

But in general going to a real 3d program will save you TONS of time. We have just about cut time to market in half versus when we used autocad for everything. Plus it allows you to spot mistakes/collisions,etc.. that might not be noticed in autocad.

Now if you do alot of surfacing then there are other Autodesk products that are tailored more towards advanced surfacing. But if you would like to switch to a true 3d package then inventor is the way to go.