Rendering issues with Directional Light in UE 4.11

Dear Epic Games,

Our team have encountered a problem in the rendering pipeline. Some “random” black artifacts. We tried to isolate the problem from the whole level and now we believe that the Directional Lighting is the cause of this behaviour together with the material setup. Artifacts appear not only on character meshes, but also on any surfaces (with some material setup), which are oriented as similar to vector of the Directional Light source. Right now we don’t understand which Material properties causing the bug. Supposably Reflection/Roughness. And this is not dependent to Subsurface Profile Shader Model (other level props and objects cause this problem too). That’s all we investigated for now.

We can send you our isolated test scene if necessary. But only privately. I’m attaching the screenshots of the problem:



Pay attention to the Directional Light vector:


Directional Light (vector) is rotated:


Directional Light is turned off:


Thank you!

Hi Dmitry,

Can you post this on the AnswerHub in the Bug Reports section so this can be investigated by the support staff?

Thank you!