Real - Time lighting via 18% grey sphere

Hello,
I'm from the Visual Effects side of things so I am hoping you can cover (or uncover) how to extract lighting information from a Grey sphere in Real - Time :
It does not have to be very accurate.

I am developing for Microsoft's Hololens.
https://www.microsoft.com/microsoft-hololens/en-us

It would be terrific if I could sample the lighting from a real environment (via a Reflection and a grey probe) to be able to integrate CG objects better into their surroundings.

Have a read of the excellent article from the makers of Unreal Engine to understand how Light & reflections are captured for use in VFX & Game engines:
https://www.unrealengine.com/blog/updated-lighting-in-templates

Can you create a script / algorithm that can :
1. capture diffuse lighting and direction from a grey matte finish sphere in real time.
2. It does not have to be accurate. Any progress via automation is a win for the Mixed Reality industry.

Do let me know If I have not been very clear in explaining what I'm going after.
Cheers,
behram