Hi Matt – We suggest removing unreal’s native fogs as trueSKY creates its own fogs and god rays, and there can occasionally be conflicts – however they can be used together if desired.
 
Using trueSKY with unreal’s volumetrics should not derive any “extra” performance costs beyond what you would expect as trueSKY posses unreal’s native directional light for its sun. And as such our lighting shouldn’t come with a larger overhead when integrated with volumetric fogs.
 
I hope this helped – let me know if you need any more help or anything explaining further.
 
Chris

Thanks Chris – below is my visual target – can I get this level of detail in close up rays within trueSKY?

I set up a quick demo of what we can achieve – as i mentioned before, since we are using Unreals native directional light the settings in there are available for use (and notably the god ray settings), which when combined with trueSKY’s atmosphere and fogs (this scene does not have either of Unreals exponential or atmospheric fog actor), and increasing the trueSKY’s Crepuscular Ray intensity produces comparable / arguably superior close up rays. 
Link to example – https://imgur.com/a/D01JPmS
 
Credit to the Scanned Poplar and Aspen Forest with seasons pack from the UE marketplace for the environment.
 
Hope this helps you and/or reached your visual target – Any questions feel free to reach out and I’ll be more than happy to answer.
 
Thanks
Chris