Hey Tim,
After spending the day testing in a new project I believe I have found the cause of the perceived ‘regression’ with shadows. It all boils down to the fact that in UE4.13 shadows are still calculated for lights that have their intensity set to ‘0.0’ . In UE4.12 a light’s shadows were not calculated if the light’s intensity was set to 0.0
This became apparent in our project because we have player flashlights and lightning FX that were disabled by way of setting the intensity to 0.0. When we switched to UE4.13 we immediately saw a performance impact because of this. For now we are going to use ‘SetCastShadows(false)’ when we disable these lights.
If you’d like to test this add a bunch of spotlights to a scene in 4.12 and notice that setting their intensity to 0.0 will disable the calculation in ‘ProfileGPU’. Create the same scene in 4.13 and notice that an intensity of 0.0 does not affect the calculation and you must instead disable ‘CastShadows’ for the shadow calculation to be skipped.
I think the desired behavior would be if shadows were disabled at 0.0 intensity. Hope this helps!
Thank you,
George