Tips
From OpenSimulator
Using Terrain commands by example
Quickly flatten a region
When you have multiple regions, that you need to terraform to a certain height, the quickest way to do it is by selecting a region, and fill the terrain to the specified height:
change-region YourRegionName terrain fill 20
Note: Remember to change to the region you wish to modify if that is the only region wish to make changes to. Without using the change-region command, you may very well end up flattening multiple regions!
