ZBrushCentral

Workflow for scan cleanup whilst maintaining ALL detail of original model

ZBrush Usage Questions
#1

I work with a lot of beautiful scan data. Sometimes I need to perform cleanup on this data (small amounts to large amounts).

Here in this example for instance, I want to separate / create a hole between two teeth that shouldn’t be ‘merged’ (arrows) and also deepen some crevices that are too shallow (line):
work with

This is a 5 million triangle model with an 8k texture.

The key thing here is I want to maintain all the detail & crispness in the new model.

The methods I’ve tried so far involve:

  • duplicate this model, subdivide & apply texture as polypaint
  • duplicate this new polypaint model & cleanup using dynamesh
  • then project the original polypaint model to the clean up version (perhaps using a morph target to prevent the original unwanted geometry to be there)
  • UV this model & bake the polypaint texture to it

The problem I have found so far is that I always seem to lose a bit of clarity / detail.

Any pointers or things to look into would be awesome.

#2

Hello @arumiat

The DamStandard brush with Sculptris Pro mode enabled should be pretty useful for deepening those crevices. You can also use the Smooth mode to “dissolve” the geometry to a degree. Settings in the Stroke> Sculptris Pro menu may help you better customize the brush for the situation. You can disable Lazy Mouse (L) for a more responsive brush at the cost of stroke smoothness–you’ll require the former more than the latter for fine detail work.

The thing is though, it would be very useful to you to be able to remesh the geometry on occasion, especially when the localized tessimated geometry starts getting too dense to work with. In those cases it would be useful to be able quickly resurface everything with Dynamesh.

So it really would be useful to figure out why you’re experiencing detail loss when projecting. If the mesh you’re projecting onto is high enough resolution, you really shouldnt see a noticeable loss in detail. Are you able to subdivide your target mesh further? If not, it may require a more optimzed mesh at base level, where fewer polygons are drawn in low scrutiny areas in order to allocate them to high scrutiny areas, which will result in much higher detail potential in those areas when subdivided.

I would point out though that in the situation of creating a gap between the teeth, you’re essentially creating detail that isn’t present in the existing model, so the color information may need to be touched up for that area manually.

You might also consider sculpting a very small subtractive mesh in between the teeth, that can be cut away with Live Boolean. It would again be easier to perform this on a mesh with a slightly lower resolution, which will require subdivision and projection afterward.

:slightly_smiling_face:

1 Like
#3

Thank you @Spyndel :slight_smile:

I have been watching Sculptris Pro tutorials & indeed it should be perfect for crevices in specific areas.

The thing is though, it would be very useful to you to be able to remesh the geometry on occasion, especially when the localized tessimated geometry starts getting too dense to work with. In those cases it would be useful to be able quickly resurface everything with Dynamesh.

Yes on the more messy scans I will absolutely need to use Dynamesh so having a method / process that let’s me use that is important.

So it really would be useful to figure out why you’re experiencing detail loss when projecting. If the mesh you’re projecting onto is high enough resolution, you really shouldnt see a noticeable loss in detail.
I suppose it is from two stages -

  1. the conversion from an 8k texture to polypaint
  2. the project of this polypaint to a new mesh
    ?

Some questions:

  1. is there a way to bake from the original 8k texture directly to the new model (bearing in mind the new model will have lost its UV if I have dynameshed) ? (or is the intermediate step always via polypaint)
  2. to capture all details from an 8k texture, is there a rule of thumb for the approximate triangle count needed?
  3. I have watched tutorials on projecting & I can’t figure our if to get the best results I need to do it in stages at different subdivisions, or just project to a very very high poly mesh?

Lastly, I should add that at some point I am going to Zremesh, UV & take into a game engine, but I feel like I have that part of the workflow down. The main thing is getting that cleaned up high poly mesh with it’s details as good as the original.

#4

Are you able to illustrate the loss of detail you’re experiencing, along with the polycount of the target mesh?

**Some questions:**
  1. is there a way to bake from the original 8k texture directly to the new model (bearing in mind the new model will have lost its UV if I have dynameshed) ? (or is the intermediate step always via polypaint)

Well, polypaint is the way you transfer the color directly to the mesh as vertex color.

2. to capture all details from an 8k texture, is there a rule of thumb for the approximate triangle count needed?

You’re going to have the best results with quad topology. Triangles are going to make oddly shaped polygons that may affect how the color displays–possibly creating a “jagged” or fuzzy appearance to some of the detail. Optimal topology for color and sculpting projection in ZBrush is evenly distributed quads, as close to square shaped as possible. You can use ZRemesher for this, then subdivide until you find the level required to accurately capture the incoming sculpting and color detail.

3. I have watched tutorials on projecting & I can’t figure our if to get the best results I need to do it in stages at different subdivisions, or just project to a very very high poly mesh?

For color information, simply projecting to a mesh of sufficient resolution at the highest subdivision level should be fine. For sculpting detail, it may require you to project incrementally, subdivision level by subdivision level in order to get the best results and touch up problem areas as they pop up. That process is described here. I would try seeing what kind of results you get using the more automated process with Project History first, because that’s much easier.

1 Like