Bump Offset with tiling layers in Unreal Engine 4

Primary Heightmap

Bump offset can be a great way to get a better sense of depth in addition to normal maps (just short of tessellation), but with VR development it is almost essential (in fact, it looks better in VR than on a mono screen).  The stereo split native in VR headsets causes the normal map to look more like wallpaper when trying to create larger normal changes.  Smaller details do not suffer as much, especially at lower roughness and more direct lighting.  Michael Abrash, formerly the VR dev at Valve, now Chief Scientist at Oculus, spoke about it here and fielded some questions in the comments.  

Primary Normalmap

Secondary Normalmap

Tertiary Normalmap

To create that sense of perspective in larger normal details a bump offset, or parallax, shader is optimal.  The need to blend multiple albedo and normal layers, some tiling at a different rates, created a problem as some of the layers seemed to float above the initial bump offset layer.  I solved the problem by isolating the main features of the bump offset node, the camera vector and height texture, and adding UV tile coordinates in separately after the fact. 

Initially, the heightmap was tiled X2, and the same UV coord fed into the coordinate input of the bump offset to tile both of the primary textures (diffuse and normal) as well as the secondary normal.

The problem arose when the tertiary detail called for a higher tile (in this case X8).

By setting the bump offset's coordinate to (0,0), it frees the camera vector and tiled heightmap of having any additional UV information.  Adding the tiled UV coordinates (red lines) into the bump offset output (green lines) allows for multiple tileable textures, each with unique tile multipliers, to be affected accordingly by the primary heightmap offset.

Seen here in this wild animated GIF, each normal map blended, first without, and then with the bump offset.  May seem subtle when getting to the finer details, but makes a huge difference when seen in the headset.