POM material only works on the floor - why ?

I followed this tutorial to make a POM material for my brick floor: How to Do simple Parallax Occlusion Mapping in unreal Egnine 4 - YouTube

Instead of feeding all that setup for UVs on POM node, I simply fed texcoord [0] into UVs input on POM node (I don’t know if it has anything to do with the issue).

After applying material to the floor mesh, it worked fine. However, if I rotate floor mesh 90 deg. to make it a wall mesh, POM material turns flat black.

What am I missing ? How do I make sure POM material works for floors/walls/ceiling ?


P.S. I am using UE 4.22.3

Download the Free Unreal Engine Content Examples, there is a level with POM Shader/Material samples, just try them out…