Elliptical arc door hole

[Anonymous]

Every time I need it, I'm wondering Archicad hasn't a empty door hole with elliptical upper arc (or better, flattened semicircle arc).
Archicad normal arc hole, if curved part is less then half the hole width, lowers arc center and creates two edges between vertical part and the arc start. I often have arcs that haven't edges at start, but are much larger than twice the height of the curved part, with the curved part that becomes a a flattened semicircle.
Even elliptical window hole has not the geometry I need, but looks a bit better than door object.
I hope that sooner or later graphisoft will add this type of arch, both as a door object and as a window object.

[Lingwisyer]

Just curious, how would you actually build an elliptical arch?

Also, I believe the Ellipse Top Window Opening object is a three point arch given the math, so no actually and ellipse...



Ling.

[Anonymous]

As far as I know, it's also not possible to make an elliptical hole in a slab for example ... or basically any 3D Element of elliptical shape.

So I guess Archicad doesn't really like ellipses other than in 2D.

[Anonymous]

Lingwisyer wrote:
Just curious, how would you actually build an elliptical arch?

Do you mean in construction?
Its pretty simple... you start with the two focal points at stills bundled with a taut string. Then start nearing the focal points and elevating the center of the string until you reach the desired arc height and you fix the focal points. After that you take a pencil and holding the string taut with it, you can draw the elliptical arc.

[Anonymous]

mbl wrote:
So I guess Archicad doesn't really like ellipses other than in 2D.

In GDL you can create solid ellipse stretching a cylinder with MUL command. And there is an ELLIPS command for hemisphere ellipsoid (but this could be less suitable). But I guess the more feasible option is to calculate mathematically the coordinates of the points that approximate the elliptical arc based on the resolution parameter.