splotches on large surface

[fraggle]

Hello,
What are your advice to get rid of splotches on large area when LC/IR map mode.
I do have a lot of Windows (7) and the room is small (20m²) but the lighting solution rely at 90% on the GI.
I used Skylight portal on each windows + store with IRmap turn on to save time.
THanks

[Bruce Hart]

Coplanar faces on the wall?

[fraggle]

No, unfortunatly,
I just crank up the IR subd to 200 and the splotches are gone; But the rendering time increase too!

Coplanar faces on the wall?

[svetlozar.draganov]

When you are rely only on GI to illuminate your scene you should increase settings quite a bit in order to generate smooth solution.
You could cut render times a lot if you add a few fill lights in the scene, this will also make the scene more interesting in terms of lighting.