Fast mobile shaders or rather Mobile! Fast!

Sort opaque geometry!•Ideal front-to-back not possible• Would need per-poly sort• Different materials•Big | Close: front to back• Rest by material•Character shader expensive• Player big, occludes a lot: always first• Enemies often occluded by cover: always last•Skybox always last• Turn skybox off on “no way it’s visible” trigger zonesBig or close (~10 meters from camera) objects were sorted front to back. Further objects weresorted by material to improve batching and reduce state changes.Although main character shader is more expensive than the scene, _but_ it always occludes alarge part of screen: always draw the character first (set smaller “render queue” in Unity)Enemies also use expensive shader, but very often are occluded by walls or cover: draw themafter regular opaque objects (set larger “render queue” in Unity).Skybox always drawn after all opaque geometry (this is always done in Unity). Additionally,since rejecting fully occluded geometry still costs ~1ms on Tegra2, special trigger zones wereplaced that would turn skybox off when it’s surely not visible.