Irradiance-only shading

If the only output from Enlighten is the irradiance texture, then the indirect lighting computation is very simple; the intensity will not vary with the normal of the pixel, so all you have to do is read from a texture:

    float3 GetIrradiance(float2 uv, float3 normal)
    {
         return tex2D(g_IrradianceSampler, uv).xyz;
    }

However, the irradiance value can be augmented with extra data as in the following sections.

Here, simple irradiance decoding for FP16 textures is assumed; when using LRB format, the decoding is slightly more complicated. See Output formats.