Hi,
When I apply a displacement map to a flat surface, perpendicular surfaces get effected as well. Is there a button I can click to toggle this off? It becomes more of an issue on more complex the model is with internal bosses and interior walls.
Oddly enough if the second surface is not perfectly perpendicular than it is not effected by the displacement map.
My workaround was to separate the surfaces, but for my purposes I need to rejoin them which required me to export to another program.
If you have a specific displacement map then the issue could be that you need to orient it correctly on the surface. Also ensure that it is applied correctly ie as a flat surface or UV etc, depending on the map.
The displacement uses a map and the normals to calculate displacement. UV-unwrapping the model to make sure your map is correct and making sure your normals are correct should make the displacement map come out correctly. You must have used a planar map here.