Acquiring and storing data in UE5

Hello! I need some help figuring out how to store Luminance data of an object accessed by the “Pixel Inspector” tool. My objective is to calculate the total light received by the object from all sources.

I was thinking of averaging the Luminance values taken from a few points on the object, but since I’ll be changing the environmental conditions repeatedly, I need to automate this process.

Could you suggest an approach for me to achieve this? Any suggestions are appreciated!