Common rendering pipeline grooming

Forward Rendering

Most common rendering , So called forward rendering , Is to string objects into a queue , Render one by one . The main cycle can be light source or object .

The disadvantage is that the efficiency is low when there are many objects or light sources , And there will be many repeated calculations .

Deferred Rendering

Divide rendering into two stages , The first stage deals with the data needed for lighting calculation , And store them in GBuffer in , These data include the location of slices 、 Diffuse map , Normal map , Specular reflection intensity diagram, etc .

The utility model has the advantages of high efficiency when there are many objects and light sources , The disadvantage is that the required bandwidth is large , Do not apply MSAA, Difficult to handle transparent blending .

Tiled Deferred Shading

Due to bandwidth constraints , It is difficult for mobile terminal to implement conventional delayed rendering , One solution is to divide the screen into areas , Render separately .

Tiled Fowrad Rendering

Divide the screen space into blocks , Calculate the range it can cover for each light source , If there is no effect on a certain screen area, it will be removed .

Clustered Forward Rendering

Forward+ Is divided in the screen space Tile Filter the light source to reduce the consumption , This division is in XY 2D Plane , and Clustered Forward Rendering Is to go further on this basis , stay Depth The direction is also divided once , Further reduce the influence range of light , Reduce the waste of lighting calculation . Because the result of the division is 3D Of Frustum, Every Frustum Called a Cluster, This is it. Cluster The origin of .