Sitoa. Create Ceiling Light

[Tenshi]

Hi guys.

I've been asking for help in several places. Need to create a lot of ceiling lights but i can't achieve the exact result with the Light Diffuser thing, those reflections has been a nightmare.
What would be the approach with Sitoa for this?

I need to use Sitoa(latest)
XSI 2015 Sp2.

[rray]

I'm not well versed with Arnold, but as a more general solution, you could try disconnecting all edges so the normals will not be merged.

Apart from that, I guess the amount of realism will be better the more things are reflected in the lamp, so with the finished room it will look the best.