ZBrushCentral

Displacement Artifacts

ZBrush Usage Questions
#1

HI All

I’m after a solution to some annoying displacment artifacts.
Firstly, I appreciate that without an extensive insight into my workflow that this could be caused by a number of things.

I’m hoping someone with more experiance than me may spot the issue straight away!

Essentially, my workflow is as follows:

  1. Sculpt details in Zbrush.
  2. Duplicate subtool and ZRemesh to low poly (around 1000 polys). Use polygroups maintain decent topology.
  3. Subdivide the Remeshed model several times and Project All to transfer the detail back onto the remeshed model.

The new mesh looks identical to the original UNTIL I get it into my 3D app.

You can see from the attached that I’m getting some strange stuff happening around the bottom of the mesh.

Any thoughts to what I’m doing wrong? Or suggestions to a better workflow ?

I did also try the ‘Divide then project ( and repeat everal times)’ method which gave different, poorer results once over in the 3D app.

Artifacts
Artifacts2340×2466 151 KB

#2

Hi @garbagematt ,

Are you restoring your original mesh prior to generating your displacement map? The act of subdividing a mesh alters it slightly at all levels of subdivision. This is a result of the subdivision smoothing process.

This is only a problem if your map is going to be applied to the original geometry in an external application. If you are exporting the modified base geometry from ZBrush and applying the map to that, it shouldn’t be an issue. In this case your problem is elsewhere.

The process for storing a morph target and re-importing the base topology immediately prior to generating a map is described both here, and in the Switch MT section of the MME documentation.

Also, be mindful of smoothing groups for hard surface models. If you have a crisp edge in your displacement map and that edge is not also creased or marked as a hard edge when it is smoothed in an external program, it could cause some drift.

:slight_smile:

#3

Once again, thank you for replying so quickly Spyndel.

If I have understood you correctly, my entire sculpt has been created inside of ZBrush.

The first time I experience the problem is when I port the mesh and the map over to Modo. In other words, the geometry originates in Zbrush rather than having been created in Modo and then importing the geometry into ZBrush for additional sculpting.

I have used this latter method on other organic modelling projects (creating a basic mesh in Modo then importing) and in these cases have applied StoreMT before I subdivide the mesh then switching it for map export once the work is complete.

My current understanding was that if the sculpt was generated entirely within Zbrush the the need for the morph target was negated beacause the maps are being generated from native geometry rather than imported geometry.

I dont do much hard surface work so I suspect I need to adopt a slightly different workflow this time.

With all of this in mind and having read the links you supplied I’m still a little foggy as to where I have possibly gone wrong, especially as we havent factored in the Project All workflow here either.

Should I still be applying a StoreMT workflow?

Thank you

Matt