Project created by Terragen, a landscape and animation generation program; contains objects, terrain, shaders, water, atmosphere, lighting, camera angles, and node network elements that make up the landscape scenes created by Terragen.

To create a TGD file, select File → Save or Save As..., name your file, choose your save location, verify that the File Format is TGD, and click Save. To open a TGD file, simply double-click the file. You can also select File → Open, navigate to the TGD file, and click Open.