In this recipe, we will look at the HLSL shader code necessary to read from the G-Buffer's resources. We will then use the screen-aligned quad to implement a debug pixel shader for displaying information from the G-Buffer to screen.
We will follow on from where we left off with Filling the G-Buffer using the same G-Buffer layout as described in that recipe, and make use of the screen-aligned quad from Implementing a screen-aligned quad renderer.
First let's begin by outlining the HLSL code necessary to extract the attributes from the G-Buffer.
We'll start by defining a structure to store the loaded G-Buffer attributes in, as shown in the following HLSL code snippet:
// Structure for holding loaded G-Buffer attributes struct GBufferAttributes { float3 Position; float3 Normal; float3 Diffuse; float SpecularInt; // specular intensity float3 Emissive; float SpecularPower; }; // Screen-aligned Quad PixelIn struct PixelIn { ...