HLSL Development Cookbook

Chapter 2. Deferred Shading

In this chapter we will cover:

• GBuffer generation
• GBuffer unpacking
• Directional light
• Point light
• Capsule light
• Spot light

Introduction

In the previous chapter, we mentioned that forward lighting has performance limitations. If you recall the basic algorithm for forward lighting, we potentially need to draw every mesh once for each light source. For a scene with N light sources and M meshes, we may need N times M draw calls. This means that every additional mesh is going to add up to N new draw calls and each new light source will add up to M new draw calls. Those numbers add up very quickly and pose a major limitation on the amount of elements you can render in an interactive frame rate.

Over the years, as graphic cards' memory ...