Tessellation isn't working

I must be missing something. I made a new material, with the diffuse, specular, roughness, and normal images. I tied all the images to the material, and I’ve enabled the tessellation to both Flat Tesselation and PN Triangles. I’ve added a constant to the tessellation multiplyer (as well as linking images like the roughness and specular to it). No tessellation is happening. What am I doing wrong? Is there some global setting I’m missing? Here’s a screenshot of the material in it’s last instance.

It looks ok in game. Actually looks pretty good, but I would still like tessellation to work. I understand that I should have it based on camera distance, but I’m not worried about that quite yet, I just want to get it working. I’m completely new to ue4, so I’m not all that understanding of how things work, but this is just annoying me T_T. Any clue on what I’m doing wrong? (I should also mention, I’m not sure what the world position offset and world displacement are, I’ve tried swapping out the images with all combinations of the images loaded, as well as constants, and nothing changes.) I’ve been trying to get this working for hours, and have searched both google (not so helpful with UE4 stuff) as well as the forums and still haven’t figured it out. Any ideas?

Hi Caliber,

your material seems to be set up correctly as far as you should see tessellation of your surface. Have you looked at the mesh with wireframe mode? Note that the tessellation scheme (at least flat tessellation) is not changing the topology of you mesh, so you’ll most likely not see a big difference.

First of all, the tesselation multiplier seems to be capped at 8. Values higher than this, don’t change anything. Have a look at your mesh in wireframe mode. Your setup is correct, but mostly you don’t have enough polygons to display the kind of detail you want, even with the tesselated mesh.

So, if you see that the tesselation works (in wireframe mode) but can’t see any differences in LIT mode, go and pre-tesselate your mesh in 3d program and have a look at it again. You should now be able to see the difference.

What GPU do you have? IIRC Tessellation requires Shader Model 4 or above I think?

Have you looked at any of the example materials so far?

This material setup won’t work. You need to multiply your height map by the VertexNormalWS node to offset vertices properly. Afterwards multiply it by a scalar to increase the intensity (otherwise the offset is max. 1UU and therefore barely noticeable, if at all).
Also disconnect World Position Offset, you’ll only need World Displacement for Tessellation.

Your material isnt set up correctly. Heres a picture that reassembles the set up that mAlkAviAn explained pretty close:

EDIT: Of course you have to use World Displacement instead of WPO. Didnt had a coffee yet :wink: Sorry. also for Tess Multiplier just use an constant 2 vector (set to 4,4 should work)

Are you using UE on OSX or win? I just discovered tesselletion is currently not supported on OSX due to openGL issues