ZBrushCentral

Need some help with this engineering project

ZBrush Usage Questions
#1

Hello Zbush community,

I am an engineer and I am working with 3D meshes created out of photo’s or scandata (photogrammetry or laserscanning).
I use software that transforms big pointclouds to a mesh, and textures it with taken photo’s.
When we make a 3D model (mesh) of a building, we always have some problems with windows. Beceause glass gives a lot of reflection, the mesh is very irregular (and so is the texture then).

We were looking for software to edit those ‘bad’ meshes, so we can make the window surfaces perfectly straight/flat. After making them straight, we can re-texture them so they look much better.
I just started learning ZBrush, in the hope it could do both (flatten the window surfaces AND re-texturing them). I’m trying to learn the basics of Zbrush, but I really don’t need to learn everything for the things I want to do with it.

Can you give guys me some tips? What tools (in Zbrush) should I get familiar with ? Or what workflow can you recommand ? Or should I use other software then Zbrush?

Thanks ahead!

These are the meshes I work with (examples)

https://drive.google.com/file/d/0B7zMNjNUX5FOOFpiRUdzWU1fVTg/edit?usp=sharing

https://drive.google.com/file/d/0B7zMNjNUX5FOM2tCSFRMQUhBeVU/edit?usp=sharing

#2

Welcome to ZBC and ZBrush BreezzBE!

I’m working myself with scan datas (Artec and PhotoScan) and ZBrush can do the job you are looking for. I can’t really give you all the information by text of course, but here are some features/functions that you need to consider:

  • Brushes like hPolish and TrimDynamic will work well to flatten areas and cleaning artifact to “polish” your surfaces. Most of the time, TrimDynamic is used first, because it’s a strong brush, then finishing with hPolish.
  • ZBrush is able to project the details and the painting from a mesh to another. It means that you need to always keeping as a “backup” your original model (duplicate the SubTool).
  • To have good results, you can “convert” a copy of your model to a DynaMesh shape. It’s a technology which let you add/remove easily volumes from your mesh. But it works only on volume, to surfaces.
  • ZBrush can also recreate a clean topology of your scans with ZRemesher which will produce a nice base mesh, ready to receive better UVs done . But you need to have a clean mesh for that first.
  • With SpotLight, you can load a bunch of textures and then reprojecting them locally on the mesh to clean. When I’m speaking with scanner users, I’m always telling them to take extra photos of the object to scan to have photos to use to clean the textures with SpotLight.
  • Spotlight like all the other painting technics of ZBrush require to convert your texture to polypainting datas (vertex painting), which will let you work without the need of UVs. At anytime, you can of course, convert the polypainting to a new texture, as soon as this new model have UVs.

Here is my usual workflow:

  • Importing the scan and checking that I have a volume (and not a lot of surfaces), then eventually closing the holes.
  • Smoothing and roughtly cleaning on the existing model all that I can do (most of the time smoothing the scan artifact) and rebuilding all the small little things which doesn’t need extra material or major changes.
  • duplicating the model (SubTool palette >> Duplicate) and hiding the non selected one (backup copy)
  • Switching to DynaMesh in a medium resolution. The goal is to fit roughly the shape of the original scan.
  • With the DunaMesh and all the sculpting brushes, I’m cleaning the larger parts of the scan which wasn’t possible to clean on the previous steps, flatten areas, adding/removing all I need, etc.
  • When done, using ZRemesher to do a new topology.
  • With UV Master, creating new UVs (eventually working with Polygroups top optimize them…)
  • Adding several subdivision level of smoothing to match the amount of polygons that have the original scan.
  • Projecting the geometry from the original scan (the duplicated mesh which was previously hidden) to the active model to grab all the details from the scan.
  • Depending of what is the source, if it’s from PhotoScan, I’m replacing the scan by the new mesh, then creating a new texture in PhotoScan.
  • Then back in ZBrush, I convert the texture to PolyPainting and with SpotLight, I’m adding/cleaning the model colors.
  • When done, I’m projecting back the polypainting to a new texture.
  • My mesh should now have a clean geometry and a clean painting.

I hope these small advises and infos will at least lead you in the good directions!