[GRASSLIST:8280] rast3 mask and interpolation

[Dylan Beaudette]

Greetings,

I have a set of 3d vector points that i would like to interpolate via RST to a 
3d raster volume. However, this data is on a hill slope, and thus it does not 
make sense to interpolate the entire "chunk" of space. rather, i would like 
to mask out everthing above and below the upper and lower bounds. I have 2d 
raster surfaces for both the upper an lower elevation  surfaces. Ideally, I 
would only like to include a thin section of elevation values bounded by the 
upper and lower elevation surface in the final interpolation. Is there 
someway to setup a 3D mask, much in the same way a 2D mask can be used for 2D 
raster interpolations?

Thanks in advance!

PS here is an image of the upper and lower surfaces that bound my volume of 
interest:
http://169.237.35.250/~dylan/3d_clay/surface-subsurface.png

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341