on older versions of unreal engine, my foliage would cull in a circle around the camera and fade in/out nicely. Now on 4.17 it just appear/disappears in weird choppy ways. It also culls as square chunks.
That is correct. To achieve the effect of culling folliage in a circle around the camera gradually, you will need to use PerInstanceFade material expression, hooked up into opacity mask slot in combination with existing opacity mask for the foliage.
thanks a lot, it worked 