To raise or lower the terrain height do the following: Backup your project first! Create a new stamper. From the Adhoc directory drag the 'For Masked Stencil' stamp into it. Click the 'Fit to terrain' button on the stamper - it should have done this for you already any way. Select 'Stencil Height' in the stampers 'Operation Type'. Set the stencil height to how much you want to raise or lower the terrain in meters. Hit Stamp. NOTE: This will raise or lower the height of the terrain by the amount you have selected, but it wont touch any game objects... you will need to make that adjustment manually.