Hi all,
During optimization for a project I’m working on, I’ve noticed that Unity terrains always draw first, due to their default queue of Geometry-100. In this particular case it was a significant performance issue due to the expensive wasted fragments that would be drawn over by other opaque geometry on the terrain (large rock formations). After altering the rock formations materials to draw before the terrain I saw a pretty significant reduction in shading cost (from Early Z rejection).
My question is, why is this the default behaviour? It seems to me that you’d want terrain to be on the Geometry queue with every other opaque material so they’ll be drawn front to back to maximize Early Z rejection. Anyone have any insight?
Ultimately terrain should be drawn end of line of Geometry, potentially in a dedicated queue after Geometry to prevent overdraw of fragments behind opaque geometry, since you usually want to spawn things on the terrain.