You need to use higher quality settings on uberEnvironment - try the presets that are supplied. Also check your shading rate isn't too high in the general DS Render Settings.

To get rid of the patchiness two main things have to be adjusted when using Uberenvironment.


(A) Occlusion Samples (larger number = higher quality = longer render time)


(B) Shading Rate (lower number = higher quality = longer render time).


Try (A) first then fine tune with (B). Also adjusting Occlusion Colour can help but it lightens the shadows.


If you have an item with transperancy / opacity map (such as hair / eyelashes) applied to its Surface then Uberenvironment render times will be even longer unless you apply UberHair Shader first to the item's Surface. Or in the item's Paramater tab turn Cast Shadows to Off.

http://www.k-3d.org/wiki/RenderMan_Controls