Missing IntegrateBRDF part in IBL?

Hey guys. I am a little confused about the IBL part…

I guess the function ‘addReflection’’ defined in reflectionPrefilteredCube(Lod).frag is for the specular-ibl-part, but it’s missing
the IntegrateBRDF calculation (with a LUT texture OR without a LUT texture(https://www.unrealengine.com/blog/physically-based-shading-on-mobile)

do I overlook something or there is any special consideration? thanks very much…: )

We don’t do that currently. What we do is what’s called “complete approximation” in the UE paper, except we also interpolate from reflection (cubemap fetched via reflection vector) to diffuse (cubemap fetched via normal vector).