[ns] using shadow bitmap in nam

[Kenji Ooishi]

Hi all,

In ns2, visiblity-based shadowing model is defined
with bitmap, like

	set prop [new Propagation/ShadowingVis]
	$prop get-bitmap environment hoge.pnm

Can I use the bitmap in nam simulation?
I would like to use it as background of nam view window.

thanks,
--
kenji