Banding and smoothing issues

Hello Unreal Users,

i’m creating a jungle scene and i notice strange banding on the surface of some of my objects (see pic), the ligtmap has size 1024

the second problem (i post them together, 'cause they may be related) is lack of smoothing in the polygons of my terrain (second pic)

any help much appreciated, cheers!


Update: the banding problem disappears if i uncheck “Cast Shadows” in the Actors Properties, any idea?

Looks like the problem was with the value “Shadow Bias” set too low…