terrainwidth X   (e.g. 512)
terrainwidth Z   (e.g. 512)
epwidth of instances (1 give 512x512 Instances, 0.5 goves 1024x1024, etc)
Jitterfactor jitters intstances by input number x half of stepwidth
Scaling Y 
Scaling X,Z
Rotation X,Z
Rotation Y
shearing amount