RAW2ASC by Doom

RAW2ASC converts .RAW files to .ASC, which can then
be loaded with 3D Studio. You can make landscapes
with it. The .RAW can be any size, but a small 32x32
or 64x64 picture is recommended, since bigger size
results in HUGE amount of faces. Use 256 gray scale
pictures. Black is the lowest point and white is the
highest.
