I have a question … because when they travel with a espefera the bolumen the texture is very well … but when you put a box or something plane displacement it is by most to him or him to go up the parameters is not achieved at least for me that the grass looks good … EXPECTING CAN HELP ME WITH THIS HOW TO MAKE FLAT IN AREAS SE LOGRE MAKE THE DISPLACEMENT AND IF YOU CAN GIVE SOME PARAMETERS
GREETINGS FROM COSTA RICA 
Re: HELP THE DISPLACEMENT
I have your same problem.When I render only a plane with grass the texture is the same of the preview, that’s ok..but if I add another solid in the scene without render, the grass become without height. Sorry for english I’m italian HELP US
Re: HELP THE DISPLACEMENT
I have also this problem.. when i try a texture with displacement it fonction well, then i add another object in the scene and the displacement do not fonction animore. So i cant use displacemnt at all…
Can somebody help us??
Re: HELP THE DISPLACEMENT
Actually i just fonud out the solution for this pb : you have to put each material with displacement in a group and it will appear correctly in the final render