You took a rather unusual approach to texturing the "boneys". Could you elaborate on that?One of the ideas for the boneys was that these decrepit creatures had been rotting and decomposing for so long that their clothes had started to merge with the organic matter of what was left of their bodies. The decision was made that instead of modeling the clothes as separate assets we would actually sculpt them into our models.
I can't think of many other situations were this approach would work, due to deformation and simulation, but for the this occasion it worked very well. To achieve the right effect, we ended up painting detailed "cloth masks" in Mari, which we then exported and loaded back into ZBrush as black and white textures. We transformed these textures into a mask so that we could sculpt the cloth form and texture exactly where we wanted it.
What were the main benefits to working this way? It allowed us to line up our textures perfectly as well as have the masks ready for our shader work later on. Instead of just layering on a cloth texture in a more procedural manner, sculpting folds and fabric in ZBrush allowed us to add just a little bit more finesse and form.
Why use ZBrush for facial shapes? Being able to see the model with its finest details, wrinkles, pores, etc. is crucial to ensure proper deformation at that level. Simply being able to see the face deform with all its details present was very helpful since our boneys did not have a regular face anymore. Many of their facial muscles and much of their skin tissue wasn't present and thus not all facial expressions were possible. You'd be surprised how hard it is to smile without lips, for instance!
We took some liberty here and there to create shapes that might not have been physically possible anymore. But when one is trying to breath life into creatures that have been dead for so many years, I think a little cheating is allowed.
What was your workflow for this? What features and techniques did you use?
All faceshapes were started in Maya, where the main masses were moved around and then brought into ZBrush as soon as possible. That's where we could check the morphs by importing the face shape as its own layer. I always had the original model in its neutral state present to ensure no skeletal features were moved around. This let us create the illusion that muscle and skin mass were sliding over the underlying bone structure. (Which should always be the goal with facial blendshapes.)
Once the bigger shapes and muscles were sliding in a believable manner, some time was spent in sharpening or softening the face wrinkles a bit to add more believability to each shape. The final morph layers were exported back into maya and the individual displacement maps were baked in. These were connected with their corresponding blendshapes through our shader. Every time an animator would dial in one of these shapes, the shader would calculate the difference between the base displacement and the blendshape displacement map and set this "key-driven displacement map" to the right value.