Displacement map doesnt match original mesh:

Jonathan85

Hello i have problems, i have this scan, hi poly few milions, i have decimated it in zbrush to around 5000 polygons, this low poly has been subdivided to again few milion polygons and i have re-projected in the subtool section of zbrush the original hi poly detail (from original model) to this low poly (subdivided several times) mesh. There were quite a lot of problems, spikes, it happens to me a lot, i do not know what im doing wrong? (check the picture below)
http://postimg.org/image/epw4hc89p/
http://postimg.org/image/42rdds5o5/

So ok, so i smoothed out the most visible ones and it looked quite ok, then i created displacement map 32 bit 4096px resolution and saved it to exr format, and wanted to use this displacement with my low poly mesh during rendering in 3ds max. But the spikes were back even though i smoothed them in zbrush... its weird... do you have any idea why is this happening and how tgo avoid the spikes at all (lowering distance in projection tab doesnt work). In zbrushg after smoothing out the spikes it looks like this:
http://postimg.org/image/7v9desm57/
Original Scan and reprojected :
http://postimg.org/image/d25vr0wk1/

jfitch

What does your topology look like for the low poly one? It probably doesn't have enough resolution (polys). Also the detail you have there is going to be tricky to reproject, you might need to edit the cage distance and smooth and move it at different sub divisions while you're projecting (ie: divide once, project, fix errors, repeat).

Jonathan85

the topogy is triangles (its just automatic decimation) i do not have the time to make the topology manually. It shoulůd have enough polys thats not the problem.

any idea how to fiy it?