I just did it..Draw the roof in plan view as if you were cutting a section thru the profile using arches and or p-lines then type 'pe' to edit and join them. It will ask if you want to convert/join..say yes..Once it's a polyline object and all the lines are connected, just type 'ext' to extrude..Type the height, then you have to rotate it to fit on the T.O.S...Hope that helps.

thanks,
in plan my roof appears rectangular but in section/elev it apears curved- i attempted the method you described above but in elevation view... the extrude command kept asking for a 3-d object and would not select the archs and lines i had turned into a pline...
what?

sorry it's late here on the east coast..I meant to draw it in an elv/section view then extrude it. After I join all the lines. i typed in ext and all it asks is for: Specify height of extrusion or [Path]:

I then type in a height, say 10', the it asks: Specify Angle of taper for extrusion <0>:

I right click again to enter, and it's there.

thanks- your help is appriciated.
i'll try again...
(ps the last line in my earlier post should have read "what then?"
not "what?"-- not that it really matters...)

if you want to draw a curved roof and extrude it in 3d, the easiest way I have done it(and I have done several curved roofs) is this:
1. go to view at the top of the autocad toolbar and select 3d views
2. scroll down to "front view" and it will give you a front view disply
3. draw your arc or series of arcs to create your curved roof
4. offset this curved roof the thickness that you intend for it to be (2 inches , 3 inches, whatever...)
5. use pline and connect each end and then go to MODIFY at the top toolbar and select OBJECT
6. scroll down to Polyline and select it
7. it will then want you to select a pline so click on the arc
8. since the arc is already a pline, it will ask you if you want to join other plines to make a single pline-do this
9. select the offest curves you drew as well as the plines you drew to connect the 2 lines and then press enter
10. select the entire object to ensure the command made all 4 individual plines into one single pline
11. now that you are in the FRONT view, extrude this roof as far back as you need to, then when you go into a SE Isometric view, you will see a curved roof extruded the correct distance you need to cover the space. Basically, drawing it in the front view makes it easier to understand. I hope that helps.
I have extansive expertise in Autocad 3D...post anything else if you need help.

Hi

You would profit from using the UCS options and knowing the limitations with the Extrude command, --- don't expect to extrude anything but closed polylines and realise that the first thing to do, is to make the Z axis paralell with your roof surface , use Plan command after setting the new UCS as soon as you can overview the drawing ------ then draw the roof as a Polyline on that new UCS and measure beforehand the hight of the extrution .
------- (or when asked for extrution hight , you can copy the measures from the drawing with (getdist))
Still the most important issue are that the Polyline are a closed one --- two arches can't be extruded but if they are connected to form a circle , then Extrude will work.

maybe this is off-topic a bit, but...

what programs do most offices use out there? I'm still in school, but for school projects, we always use VectorWorks, which I like a lot. At the office where I'm interning, they use ArchiCAD, which I'm beginning to understand and like a bit and they used to use VectorWorks. The only time we ever use Autocad at the office is when we need to fix someone's engineering drawings. I'm not very good in Autocad at all, which is probably why I don't like. VectorWorks is still tops in my book since to me it's the easiest and most intuitive. Any thoughts? What do y'all use and why?

no doubt there are more seats of Auto Cadd in the world than anything else combined...

Hi

You must consult the manual