OT 3D geometry - please help

[George Ioannidis]

Well, I am stuck with construction problem and need help. Please see attached.  Any suggestion will be highly appreciated.

[Miguel Tano Adanes]

Which is the ray of the curve that is tangent to A and B? Let me think a little bit and I'll attach a sketch.

[Ros. Riha]

what exactly is the problem? from your sktch it seems as simple matter of extruding, adding and substracting solids...

[Roy Hirshkowitz]

It's more complex than you think-- curving in two directions.  Not saying it's impossible.  I'll see what Scott thinks about building it in Rhino.

[George Ioannidis]

Yes, Roy, it is really complex. Though I think I did find a satisfying solution. I made an internal and external ellipse using the two lines D and E as points on their axes. Then I did loft on those two ellipses, which produced a solid. this solid I subtract then from extruded first part of cylindrical part.

[Ros. Riha]

not trying to be funny, but - what did I say on the first place? It is going to be just couple of solids extruded, added and subtracted.

The point I am trying to make is: once your field of expertise is architecture and architectural rendering, you should start to be really worried once you find you cannot accomplish what you need using simple AutoCAD tools - the thing you are modelling is going to be built and tools they use to make it really real are similarly crude as AutoCAD ones.

simplify.

[Miguel Tano Adanes]

@Ros:

this is partially true, up to a point, which is when things you're talking about belong to contemporaneity.

Everything changes when you're dealing with old buildings and other hand-made stuff.

[George Ioannidis]

Ros, your point is only partly true. Sometimes it is easier to make something in the real world than in CAD (and I mean AutoCAD). I can do this easy in computer e.g. in Blender, but the result can't be used in AutoCAD, as it will be mesh, so no booleans, no subtractions etc. back in AutoCAD. The model I tried to do will be made of poured concrete. The form will be made from steel plates which will be hammered until they fit the curvature of outside part, then the inside half will be made to fir exactly the outside shell. I'll pass the model from Acad to Blender in order to unfold it as pattern to be plotted in 1:1 scale.

[Miguel Tano Adanes]

I actually got the same result. My question about the ray was because I didn't see the heigh of point D so I though it was a circle.

Check this.

[Zdravko Todorovic]

bravo maestro

[Roy Hirshkowitz]

Nice.

[Ros. Riha]

Indeed, looking forwards to renderings...