Irradiance Map for Diffuse Ambient Light

Hello everybody,

I have a set of Diffuse Irradiance Map encoded as Third Order Spherical Harmonics Coefficients. I am trying to use it as ambient diffuse light for my entire scene.
I am not sure if its possible to accomplish this goal with the built-in Sky Light or the Ambient Cubemap in a Post Process Volume.

I`ve also tried to create a material that computes the resulting pixel color for a given Set of Coefficients, but I was not able to use it effectively.

I would appreciate any tips or information that help me to accomplish this task.

You need to compute resulting diffuse light and multiply that with albedo and output that to emissive channel.