Ground shadows default or flat?

[Cy-27]

With default setting, the fps is low at low altitude. What's their difference?

[Canada_Moose]

With default setting, the fps is low at low altitude. What's their difference?

 

 

Flat shadows don't follow the contours of the ground etc so they get cut off and can look a bit odd.

 

 

I use flat because the FPS impact is far less.