The export to Unity RAW Terrain/Texture command creates a RAW terrain
file with unsigned 16-bit values scaled from 0-65535 for the elevation
range of the data being exported. It also creates a JPG texture file covering
the same area as each RAW terrain file.
The RAW file is flipped horizontally and the JPG rotated 180 degrees to
conform with Unity requirements.
If not exporting the full extent, first specify the bounds for the export
on the Export Bounds tab and then either specify the sample spacing (resolution)
to use for the export or use the Tiling tab to define your own tiling
scheme. The terrain and texture sizes from the main export tab will always
be used, the resolution is will change with the use of Tiling options
on the Tiling tab.