Steht auch im Manual.

Kann man mit den Dataiendungen lösen.

(d3d_lodfactor[3] und die Erklärungen bein Entities)

Quote:
If an entity file name ends with "_0", it is assumed that similar files ending with "_1", "_2", "_3" are the three further LOD levels for that entity. For instance for "house_0.wmb" the engine expects "house_1.wmb", "house_2.wmb", "house_3.wmb" as LOD files.