Terragen Terrain File (.ter)
The TER file extension, short for Terragen Terrain File, is used by Planetside Software's Terragen program to store terrain data. These files contain altitude information referenced by Terragen to generate natural scenery, including integer values along the x, y, and z-axes to specify terrain dimensions. Introduced by Planetside Software, TER files facilitate easy terrain transfer and are integral to digital elevation modeling in computer graphics.