problem with grass displacement

[albertoalban]

hi im new in here i need your help, my english is not so good but ill try to make my point clear, im having problems with the grass when i use the displacement, the displacement occurs on both faces of the plane, i neeed to know why and how to fix it, it lifts the plane too, please someone help me

 

here u can see what its happening :

[Nicolai Bongard]

You could try to set the shift to half the displacement amount. So if your displacement amount is 10 cm, try to set the shift to -5. Also make sure that there is no blurring on your image, set it to 0, or 0.01 or whatever the minimum value is. If your displacement image is a jpeg or some other compressed format, the intended black parts of your image may not be 100% black, and therefore still get some displacement. Make sure your displacement image is in a uncompressed format, like perhaps a PNG.

[John Dollus]

make sure you are displacing a plane and not a box with 0 thickness.