Scatters objects in the terrain area, randomly creating new object positions. Usually it's the first generator that starts the objects nodes chain.
Unlike Random generator, it virtually places objects in an ordered grid, and then offsets their positions at random. It is much faster than the Random node and mostly suits the most cases. However Random still might be needed for some "true random" scattering.
Seed: a number used to initialize pseudo-random noise generator. If two generators use equal seed numbers the resulting pattern will be the same.
Density: the quantity of scattered objects per a square kilometer (100x100 units). Note that since are objects are placed at random within terrain tile + margins the total number of objects within tile itself might differ both in bigger and smaller sides.
Density: 10, 100, 1000, 10000
If the Density value is below 1 (presuming terrain size 1000) it will scatter objects on some of the terrains only, leaving others empty.
Uniformity: how close the objects stay after being "virtually scattered" in grid. If the value is 0 the object could be placed anywhere within it's "grid cell", if 1 it's not moved and pinned in "cell center".
Uniformity: 0, 0.1, 0.5, 1
Relax: in some cases, especially when the uniformity value is low, the objects could be scattered too close to each other - for instance, when one object moves (1,0) from it's cell center, and the one to the right (-1,0). So after the objects being scattered the generator applies a positions smoothen algorithms, pushing away the objects that are too close.
Relax: 0, 0.5, 2, 4