tree_range

Controls the 'granularity' of the Adaptive Binary Tree (ABT) that the engine uses when a Binary Space Partition (BSP) tree is not available.
  The ABT divides the level into rectangular regions; tree_range gives the average size of a region. The smaller the value, the more 'fine-grained' is the tree and the less objects are contained in a region. On a dense populated level, smaller ranges can be advantageous. However a small range requires frequent tree adaptions when many objects are crossing region boundaries. So do some experimentation for finding the optimal tree_range for your project. Note that this value is only a hint for the engine; ABT regions vary in size depending on the level geometry.

Range:

100 .. 10000 (default 1000).

Type:

var (to be set before loading a level).

Example:

tree_range = 2000; // coarse-grained tree, bigger regions

See also:

Culling, Lighting