Making Of 'Traditional Portrait Bust'
Character artist John Crossland shares his techniques and tips for creating a classically-inspired portrait bust in ZBrush and Maya.
At the moment I'm concentrating on further improving my speed, spatial awareness and workflow. The concept for this piece was to do a study of a male adult, sculpted and rendered in a classical style. Using DynaMesh is a good basis to work with digital clay, starting from a small form and developing the piece all the way through to completion. During this making of I will take you through some of the features of DynaMesh and how it helped me to get to a final rendered piece.
I usually start my projects with a quick image search to get a feeling for what I want to do, although I have a very large and extremely useful collection of saved images that I have come across previously. I find this really handy to browse through when I'm in need of some inspiration. I never really have any clear plan with these types of studies; I find it far more interesting to go with something that fires my imagination and see where it takes me!
Base scale object
Once I was happy with the idea, I created an asset which helped me get the correct scale, as well as letting me know which way the sculpture will be facing. Later on I would render the scene using a 'real world' physical lighting setup, so I needed this asset to be on a 'real world' scale.
I started working with a cylinder primitive, and then subsequently created a measurement tape to a scale of 1 foot, measuring the cylinder against it. This meant that when I imported the cylinder into ZBrush I knew I was the right way up and was working to the correct size needed. Sometimes with ZBrush it can be difficult for me to recognize what scale I am working to, so it is a really useful asset to have for future reference.
Initial form building
From the base cylinder created in Step 2, I then selected DynaMesh mode from under the Geometry tab in the SubTool palette. I tend to start with a fairly low mesh of about 16 to 32 resolution and start roughing in the basic forms of the sculpture. As I started to stretch this mesh I re-DynaMesh using the masking function; this helped to keep a clean mesh as I continued to develop the forms of the sculpture. Then, when I began refining further, I increased the DynaMesh resolution to 128 x 256 to give me more control when sculpting the finer details. I usually stop and jump out of DynaMesh at this point.
Refining the sculpt
As I continue to develop a sculpt I generally only use a few brushes. The Clay and Move brushes are my favorite for building forms and details. I will use the Slash brush for marking in certain areas, but then always take care to smooth out the surface afterwards.
Once the secondary forms have been developed even further I will then sub-divide the mesh. I find that DynaMesh provides a pretty stable quaded mesh that divides well, giving me enough resolution for the tertiary forms. At this point I also started adding in some simple asymmetry as well.
At this stage, once I'm happy that all the forms are roughly in place, I start thinking about producing a semi-to-final remesh. This will help later for performance, posing and final detailing, not to mention reducing file size.
I duplicated the mesh so that the original remained safe, working on the copy. I defined a few ZRemesher curves on this copy, meaning that ZRemesher understands where we want the topology to flow. With the default settings on, I run ZRemesher, checking over the topology. If I need the mesh to be a lower resolution I will re-run ZRemesher with Adapt and Half on; this retains the newly-defined topology without having to draw new guides. Then I append this mesh back together with the original sculpt.
I subdivided the new appended mesh a few times to give it a higher resolution for the re-projection; if we didn't do this we would subsequently lose our sculpted details. Next I ran the Project All function (which can be found under the extended SubTool palette). Usually the details transfer perfectly but sometimes there might need to be a little mesh clean up or I might need to change the projection distance.
Final details then decimation master
Now that the topology of the sculpt was clean, I continued developing the finer, more subtle details, adding in further asymmetry and expression. The steps previously taken with ZRemesher made posing the sculpture relatively easy, and with solid topology I could step down the subdivision levels and mask off parts like the head and neck. This helped pose the model at a lower poly state instead of trying to manage a denser mesh, and this way the performance was generally more stable.
When I was finally happy with the model, I decimated the mesh. To do this, first I ran Pre-Process; this analyzes the mesh and lets me determine the optimum polygon limit for decimation, usually around 40k. Typically this involves setting the decimate slider to approximately 10 or 20%, and then hitting Decimate. Decimating retains all the details of the sculpture but cleverly outputs a relatively low poly asset for faster rendering; this helped me avoid having to generate UVs or bake textures to get the high resolution detailing.
Rendering in Maya with mental ray
I imported the decimated mesh as an OBJ from ZBrush into Maya for rendering. Generally I like to set up a simple lighting studio consisting of a floor backdrop, shadow light, rim light and some additional bounce cards for reflections. I rendered with Final Gather enabled to get some realistic soft light to bounce off the sculpture. I'll also added exposure control to the camera and some bokeh depth of field.
I also like to use the shader Mia_Material_X for rendering as it employs physically correct materials settings that can really accentuate clay-like materials.
Final clean-up in Photoshop
With the final render opened up in Photoshop, I did some minor color corrections here with a Levels layer, and also added in a little atmosphere using the Lighting Filter. Sometimes I'll use Photo filter to add in some soft warm colors and have recently been doing a bit of experimentation with Color Lookup files (this function is one of the new additions to Photoshop) – this can add some interesting visual effects to really show off the final image.
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