So if you use a cylinder as the cutting object, you will find conics




If you use a cone as the cutting object, there will be no conic

Yeah usually the definition of a conic section is a curve formed by the intersection of a cone and a plane, with different angles of the plane making different types of conic curves.

If you are intersecting things other than a cone and a plane then you may not generate a conic section curve as output, although they still might be generated if you have things arranged in particular ways.

Does that all answer your question Pilou?

- Michael

Nice model.
Google search came up with "Intersection of quadrics"
There is a QI program and 4 research papers. http://hal.inria.fr/docs/00/18/60/89/PDF/JSC1.pdf
(Google each of the 4 research paper titles to find them.)

The little "parabolic" looking curve is not an ellipse, not a conic, and is not planar... it is a "second order curve...."

Thanks, that is more clear now! :)

Ah Bemfarmer,
You are the man!



My conic = 0.4653, 0.4652, 0.4333 My curve = 0.4652, 0.4653, .4332

The "non-planar" was the givaway!

It Was a mistake, though it lead me to my solution! I wonder how many of these have created solutions in the past!!!

Thanks for chiming in. :)

You have made my last hairs losted! :)
A conic curve is always "flat" :)

Frenchy,

a conic curve is derived from running a plane through a cone at some angle. It will be planar. I suppose a conic who's "view" is planar, but curves out of plane, becomes somthing else.. Maybe bem can be specific.