Volume Rendering Technique in VisAD

Dear All,

I'm just wondering what sort of technique is being used for Volume Rendering
in VisAD. Is it "Splatting", "Spatial Technique", "Blending" or something
else? Hopefully someone can answer my doubt. By the way, may I know which
particular file(s) in VisAD package is attached with this Volume Rendering
code. Thanks n Cheers.