Any object in Max can be set as a terrain object. The geometry of the object is not important and will not be exported. Only the position is relevant and some properties.
To set one object as a terrain object name it "_terr_something". The object must have all these properties:
"CELLSIZEX" : how many meters (X axis) will be one pixel of the
heightmap when rendered in game. 1=1 meter
"CELLSIZEY" : how many meters (Y axis) will be one pixel of the heightmap when rendered in game. 1=1 meter
"MAXHEIGHT" : is the max height of a white pixel on the heightmap in meters.
"HEIGHTMAP" : is the name of the heightmap file used to displace the terrain
"MATERIALMAP" : is the name of the materialmap file used to paint the texture on the terrain
"LODDISTANCE" : is the distance where it ends doing lod, and just uses a flat texture
You have to export the level with "Export as Terrain Level" in exporter
You have to use gfxpackage enabled for NR. it will never work on OR
Copy the world file in the gfxpackage/levels/something dir as always. Plus you need two files in the same dir: the heightmap and the materialmap
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