   skybox drawing : what's more efficient ?
  I wonder what's the more efficient method for drawing skybox :1) start scene rendering with skybox, with z buffer disabled2) end scene rendering with skybox, with z=zFarthank you   
  The latter (since the occluded parts of the skybox can be early-depth-eliminated). But only when the z=zFar is done in the vertex shader.Don't play around with depth ranges and always clear the depth buffer, to ensure the GPU's optimization stuff to work with the depth buffer.Okay, I'm sure someone will describe you in detail with proper terms.   ;  thank you !   ;  ^^ What he said ;)There's details in this recent thread on the subject.   ;  Be careful with drawing the skybox last. If you have transparent textures in your scene, they won't render correctly. The transparent portions of those textures will blend in the clear color of the colorbuffer for the background instead of the skybox texture, if there are no opaque objects behind them.In general, if you have transparent textures (alpha-blended) in your scene, then you need to draw opaque objects first (including the skybox), then transparent objects by depth (back-to-front).   ;  thanks for these details about transparent/opaque objects, I was about to make this mistake (ie drawing the skybox after all rendering instead of after all opaque drawing) ;)   ;  .... I would also add that I must set the depth-test to 'less or equal' while rendering the skybox, because the z-buffer cleaning value is equal to the skybox depth in projected space (1.0f)