I’ve been working with Zbrush for several years but am finally getting around to posting on the forums for the first time. I learned Zbrush a few years back as my modeling tool of choice for cleaning up 3D scans I made with a kinect scanning rig that I designed: https://www.thingiverse.com/thing:127968 , and I used these scans as part of a big art installation in which I 3D printed a model of turn of the century Coney Island’s Luna Park. This is the piece as it was installed in the Coney Island Museum up until this past winter (the tower in the foreground is 6’8" tall.):
This spring I was selected for a TED Residency, and have been revisiting the project as a VR Time Machine that allows viewers to walk through the park, as well as hop in time to various parts of its history. Because my previous models were all super high poly files for 3D printing, I’ve been getting pretty good with Zmodeler and redoing them as lower poly versions, then exporting them as OBJ for importing into Unity, where I am developing the experience. I have some questions for the community specifically about scale AND polypainting/texturing, but first some process shots:
Finally, here’s a few screengrabs of the current build in Unity- I have been playing with using a cell shader and like the stylized look of it, although the plan is that once the modeling is done, I will come back and do a texture pass. All these buildings were covered with a quarter million tiny electric lights, and the plan is to create an emissive texture in the pattern of the electric lights.
So a few questions for the community, regarding issues I have been dealing with.
First- regarding workflow- Ideally I am only working in Zbrush, and not using any other 3D software. I have been working on specific buildings with many different subtools, then merging those/ exporting them as OBJ, and bringing those into a master park layout file, from which I export each building as an OBJ, which is pulled into Unity. This preserves registration and all I have to do in Unity is apply material shaders to each of the polygroups in the building.
Issue #1 I am having is with scale
Is anyone else out there bringing zbrush models directly into Unity? I’d love to learn more about your workflow. Here’s my issue: Its my understanding that Unity works best when things are set to actual size. Being accustomed to 3D printing work, I am used to setting sizes in millimeters. Using Scale Master and the transpose tool, I originally set the main tower of the park to its actual size- 200 feet tall, but in millimeters (60,960 mm). However, when the model was imported into Unity, the tower appeared to be ~60K meters tall, or off by a factor of about 1000. I ended up scaling the model way down using Transpose Master, so that now it exports into Unity at what seems to be the correct scale. However, this means that in Zbrush the master park layout file is insanely small, making it hard to use tools like transpose or Zmodeler. Ideally I can use Scale master to unify the entire park layout model and then set scale properly- does anyone have any advice for me on this?
Issue #2 Polypainting textures
I have to confess that as a 3D printing person, I know next to nothing about polypainting and need to really learn this part of the program. I would like to be able to generate a texture in the form of a dot pattern to imitate the patterns of electric lights that covered all these buidings (see below- in Unnity, I can make the texture an emissive light source to give the illusion of the hundreds and thousands of lights). The issue I am finding is that polypainting seems to be vertex color and does not seem to work with lower poly models. Should I be diving the models to paint them and the export the texture to be wrapped on the lower res geometry? If anyone can point me in the right direction as far as this workflow, I would be greatly indebted to you. Any links to specific videos on doing this would be extremely helpful!