Geografic-Information-System/raster3d/r3.null/r3.null.html

<h2>DESCRIPTION</h2>

Modifies the NULL values of a 3D raster map.

<h2>SEE ALSO</h2>

<em>
<a href="r.null.html">r.null</a>
</em>

<h2>AUTHORS</h2>

Roman Waupotitsch, Michael Shapiro, 
Helena Mitasova, Bill Brown, Lubos Mitas,
Jaro Hofierka