Terrain Scattering

Scatter instanced assets across the terrain at varying LOD levels. Provide example.

Goals

• All terrain scattering assets each share a single instance geometry thingy (as opposed to a new one for each chunk)
• The location of the assets should be stable (not change randomly based on new chunk lods coming and going)
• The locations of the scattering should be driven by a map, per asset / scatter, so that the user can e.g. place trees in low lying areas, ask off oceans and water, and avoid placing assets on terrain chunk skirts