World Displacement low in detail

[anonymous_user_f8d1c0cc]

Hi, I have been working on some materials in UE4 and am having issues understanding world displacement and how I can make a material have realistic bumps. I am struggling to find good documentation on this topic anywhere else. What I want to do is make each rock on my asphalt texture look like it is 3D. I have my material set up like this:

I have been trying to get there to be some tessellation when the material is applied but I can only seem to get very little tessellation:

Setting the tessellation multiplier to something like 10 thousand has almost no effect and I can’t understand why.

Help is appreciated, thanks.

Edit: A couple more screenshots showing what the road looks like and how there is barely any 3-dimensionality to it.

[Deathrey (DeathreyCG)]

Tess multiplier is capped at 15. The idea is that you should supply a denser base mesh to start with.

[anonymous_user_f8d1c0cc]

Do you know how I would go about doing that? The lines on the road are meant to look like paint on the material so making a denser mesh might be hard for me.

[anonymous_user_f8d1c0cc]

Turns out you have to subdivide a surface, as tessellation works on a per-face basis. After 4 subdivisions the displacement quality has gone way up.