Using World Machine terrains you and the .ter format you will likely run into a current bug in World Machine where the heights get exported such that they have a significant negative offset when used in Terragen and Terragen 2. To resolve this directly in TG2 simly add a Heightfield Adjust Vertical operator from the button below the terrain node list and then adjust height to the intended value. You can also fix this in TG 0.9 by rescaling the terrain with Set Height Range in the Modify dialog. Set an appropriate max and min then resave the terrain. It can then be used in TG 0.9 and TG2 with no further adjustments.
This bug is fixed in the next version of World Machine.
- Oshyan