ZBrushCentral

Fine detailing in mold making

ZBrush Usage Questions
#1

Hi everyone,

I am using Zbrush for creating chocolate molds. One thing I’m struggeling with is adding fine details on (flat) surfaces.

Please see the examples in the picture: very fine lines, lettering, drawings, etc.

IMG_2901
IMG_29014032×3024 239 KB

I have managed to extrude clean shapes from alphas:

  1. polygroup a masked alpha
  2. smooth out the polygroup edges
  3. extrude inwards using zmodeler

But this gives me a couple of problems:

  • grid-like drawings lose their straight and angular details when smoothing out
  • these extrusions have a 90° angle inwards – they go straight down.
    However, as these models will be used for moldmaking, a minimum draft angle of 4° is required.

I have not found a decent way to do this yet, so I was hoping anyone could suggest a solution and/or better workflow to get these kind of things done.

In short, what I’m looking for is a way to extrude very fine details, inwards at a certain angle or curvature.

Thanks for helping

#2

Hello @jvanaken ,

It’s possible I may not be understanding all of your concerns here, but there are any number of ways to stamp or press fine detail into a mesh in ZBrush. However, your strategy may change depending on your output needs. A piece being exported for print will have different needs than a piece exported for digital render.

The basic principle here is that you need enough resolution in your mesh to capture the fine detail, and the quality of your topology will also affect the results you get. You may be able to get clean results with fewer polygons if your topology is sufficiently optimized. The optimal topology for getting good clean sculpting and painting results in ZBrush is evenly distributed quads, as close to square shaped as possible. This detail can be stamped into meshes in many ways, including:

  1. Alphas. The DragRect stroke type may also be useful in drawing out logos and patterns.

  2. Spotlight

  3. Stencil

  4. Projection Master

  5. UV based textural solutions.

  6. Noisemaker

While some features in ZBrush are intended for the shaping of form and work only on a mesh with a single level of subdivision, this limits the mesh’s capacity for surface detail. For fine detail sculpting, at a certain point you will want to transition to a multi-resolution mesh with a clean base level topology, and as many subdivision levels as are necessary to capture the detail.

If you plan on exporting this detail for digital render, you will need the mesh in this form to create and export displacement maps for the display of that detail on low poly meshes for rendering in programs that can’t easily work with millions of polygons. ZRemesher can be useful for quickly drawing adequate base level topology for good sculpting results in ZBrush, and detail projection can be used to transfer the detail from a previous high resolution for of the mesh to the new multi-res mesh.

If exporting for print, concerns about topology may be fewer, and you may simply want to Decimate the high resolution mesh for import into a slicer.

Good luck!

#3

@jvanaken

Another option for the details is to model then as separate subtools and then Boolean the main body of the mold with the detail subtools as cutters. That way you can easily control tapers, bevels or other features of the detail. For example, use the Text plugin to make lettering and cut from the block. Use array mesh to take simple shapes like rectangles and make grid patterns. Bevel and/or taper bottom surfaces to get the draft you need for a physical mold. Use Live Boolean to adjust position and depth live so you get exactly what you want before finally creating the boolean result. Anyway, it’s Zbrush so countless ways to get something done. Good Luck.

#4

Ah, thank you for pointing out these things to me, just what I was looking for.
So many ways things can be done in Zbrush, it’s nice to know where to look :slight_smile:
Also the boolean suggestion is interesting, will definitely check this out.
Thanks!