4 implementations of Deferred shading

Method 1. Forward Shading

1 pass of rasterization

• 100 lights of random positions and colors

Method 2. Simple Deferred Shading

2 passes of rasterization

• geometry pass which produces position, normal, albeo textures with depth testing
• lighting pass for shading without depth testing

Method 3. Deferred Shading optimization with light attenuation range

By using actual effective range of each lights, shading stage is reduced.

Method 4. Deferred Shading optimization using stencil buffer

Considering the parallelism of GPU, each light executes the fragment shader only for affected pixels.

• Reference : https://www.ogldev.org/www/tutorial37/tutorial37.html