How to create 3D arc/elipse between coordinates

[Harmison]

I am just curious that whether there is a way to make a circle or ellipse between coordinates that are not parallel in UCS. I'm using autodesk map 2005 but have also access to Autocad 2005.

[Hussain]

I don’t think that you can create a circle that is not parallel to the plane of the current UCS. You will have to create a new UCS and then create the circle.

[Harmison]

I have 4 coordinates which is not in parallel (measured with total station on site) and it is not quite a circle, more like ellipse.
So how do I draw an oval (circle/arc like) line in 3D, or between these 4 points that i've taken from the total station.

[Hussain]

One way to do this is to approximate the arc with chord segments using a 3d polyline. Some 3rd party software reduces survey data in this maner.
You can find a very useful utility from the below site:
It appears 3dutil.cip at http://www.cadresource.com/library/lisp0a.html
may be what you are looking for.

[Alban]

You can use the points to make a new ucs, then use the points to create a 3 point circle.