"Nearest" drawing-curve for IvBalloon

[#1]

There should be a different (set of) parameter(s) for IvBalloon that "simply" allows the balloon to be connected to the nearest drawing-curve.  Currently, the user must name an edge and that edge must resolve to a drawiing curve in the view -- difficult to get this right.  For IvBalloon, the easiest solution is just to allow a value of :Nearest for the "entity1" parameter.

[#2]

I was thinking about this and would like to add a suggestion.

Since there are two issues that happen here, I hope that both can be addressed.

1. The named entity can exist on the part, just be not visible in the view.

2. The named entity can exist in some configurations of the part, but due to features turning on and off the named entity could just not exist sometimes.

The idea above would handle case #1.  It would not work for case #2 and we would need another way to handle this.

I think a good way to handle case #2 is allowing a named workpoint.  It would probably be the answer to another idea that was posted (http://forums.autodesk.com/t5/Inventor-ETO-IdeaStation/Drawing-Balloons-Leaders-use-Workpoints/idi-p...  This way, you can be guaranteed the workpoint isn't disappearing in the part, and then you just find the closest drawing curve to that workpoint.

Thoughts?

[#3]

I am thinking that you don't really need a drawing curve as opposed to a face, i don't know if that makes it even simpler.