Hi @Luulaalaa_A
Displacement map issues are always possible due to the dizzying number of variables in a displacement workfkow across separate programs. But this in itself should not cause them. In this case you’re creating an entirely new mesh UVs to map the high res detail to. The old mesh only displaces the new mesh with its high res detail, and then plays no further part.
What will cause issues:
-
Differences in UV smoothing settings between programs.
-
The act of subdividing the new mesh. The act of subdividing a mesh slightly alters the form of the model at all levels of subdivision. This is an unavoidable effect of subdivision smoothing.
So if you create your new base level topology and create UVs for it, that will remain unchanged until you subdivide it , which is necessary to capture the detail from the previous mesh. However as soon as you subdivide it the form will shift subtly, and this may create drifting issues with the displacement map if it is generated for that altered geometry and then applied to the original, unaltered mesh in an external program. If you export the altered geometry directly from ZBrush and instead apply the map to it, there is no issue.
To avoid this in the cases where you will be applying the map to the original, unaltered geometry in an external application, it is necessary to restore the original form of the mesh immediately prior to creating any displacement map. The recommended way to do this is to store a morph target, then import the original geometry back into the base level immediately before generating the maps and before again changing subdivision levels (which will again cause the mesh to shift).
The process for doing this is described in the texture generation documentation, and also in the “Switch MT” section of the Multi Map Exporter documentation.
Good luck!