Skyline Barrier silhouettes question

[RobStauder]

Hi all,

I wonder if I'm missing something obvious here. I'd like to use the skyline and skyline barrier tools to generate visible and non-visible areas around some features in a local scene. 

I run skyline twice, with and without the Create Silhouettes parameter checked. 

Without silhouettes, I get the areas visible to the observer.

With silhouettes, I'd like to get the areas silhouetted from (not visible to) the observer. But instead, I get this - 

Here's another view of the silhouettes - 

I know the doc indicates - 

This tool can be used to create feature silhouettes that can be extruded into shadow volumes using the Skyline Barrier tool. The shadows generated through this process will be created at a slight offset from the geometry of the input features. 

But this seems to be more than a slight offset. 

Any ideas on how to make the silhouettes be true silhouettes from the observer? Or should I just brute-force something in 2d and arcpy? BTW the exploratory analysis Viewshed tool is awesome, but it doesn't give me an output.

Thanks!

Rob

[RobStauder]

I abandoned Skyline and instead used Construct Sight Lines, then Lines of Sight. Then I did pairwise buffer with dissolve and a very small distance, followed by union. I used erase to remove the "visible" areas from the non-visible areas of the silos, then used make feature layer several times to remove features outside the unioned areas. Here's the result -