Hi Brian - I don't think it will work to make a non-interactive arc continue, since the arc continue factory is set up to work with an osnapped point as its first input.

That's another variety of point (IMoiPickedPoint) that is generated by the point picker, in addition to containing an x,y,z point in it it also contains a list of snaps that were active for the point, and the arc continue factory finds the curve to be tangent from by going through those object snaps.

There is not currently any way to set up a "picked point" other than having it generated from a pointpicker pick, so I don't think that is one that you will be able to automate currently.


Conic should be possible to script though - the inputs what you wrote, you need the first 3 inputs set to points (these can be regular x,y,z data points), then set either the 4th input (with index = 3 since they start at 0) to a point for the "through point" or instead of that you can set the 5th input (with index = 4) to a rho value which is a floating point number.

If you want to specify a "through point", then leave the rho value completely unset, and if you want to specify a rho value instead then you can leave the "through point" input completely unset. Let me know if you still have problems with it.

- Michael