dome roof

[Anonymous]

hi i am new to archicad and i need to know how to create a dome / curved roof in both directions (i.e it will look like half a rugby ball)!
sorry if this is such an easy take and i'm just being dumb.
thank you
ash

[Anonymous]

Unfortunately the roof you want to make is quite difficult. Sorry to say, the easiest way I can think of to do it is with GDL. If the form you are looking for is elliptical in plan, you can make a dome roof with the roof tool, save it as a library part, and stretch it.

[Dwight]

Many forms can be made simply by redefining how we think of them. By imagining the form as a roof, it leads us to being bounded by the limitations, however pragmatic, of the roof tool - tilted prisms....

If you think past this, the profiler is your answer, but it is not just one step to learn.

The profiler - not automatically installed but residing in your goodies folder- extrudes a shape along a path or rotates a shape around an axis.

The principle you'd use to make half a football is to define the profile of the extended dome and execute the profiler command.

This results in a 360 degree football on end. In the element dialog, you reduce the sweep to 180 degrees and apply an angular offset to lay the shape down.

The object I made required an increase of resolution - I inadvertently had the magic wand setting rather coarse and adjusted the RESOL of the dome in the GDL 3D script of the element

[Dwight]

here's a rendering

[Dwight]

here's the shape in plan and the generator shape

[Dwight]

The GDL object and edit issues - the object can also be tilted and the sweep reduced in the object dialog box.

Study the profiler instructions, as meager as they are, but this is a novel use for it that will yield all your symmetric sweeps and extrusions - look to the Solid Element Operations for sllices and edits of these profile objects....

[Dwight]

Elements made this way are also parametric - they can be stretched and squished and changed in height - all within the same topology defined by the original curve.

So do not despair if your original curve isn't exact - there is some boomf in the deal.