The Mursi Tribesman image was a way for me to test out different techniques I had learned during my four years at school. Realism was not my focus in this piece but rather creating a painterly CG illustration that I could have printed on a canvas. This way I could test my modeling, texturing, lighting and shading skills all in one project while still working towards my degree.
I started off by finding as many references as possible. I wasn't sure exactly what I was going to create but I knew it was to be witch doctor-esque. I ran across the Mursi people of Ethiopia and found their traditional head dress and the contrast of their AK's to be an interesting subject matter. I decided I wanted to make a tribal elder or leader. His frail elderly body contrasts with his position of power within the tribe as well as his calm but controlling gaze.
I began sculpting with an old base mesh I had saved from a previous project. I brought it straight into ZBrush and began pushing and pulling with the Move tool to achieve the general proportion I was after. Once I was happy with proportions I broke out the Claytubes brush and began sculpting in secondary forms.
I try not to skip ahead at any one part of the model and over-detail it early on. During this stage I focused very heavily on muscle, bone and overlying fat deposits. I started with sculpting the muscles and protruding boney structures in the correct position and then layering the body's fat deposits over top. The sculpt has a more natural look to it when I take this approach, and once the muscles are sculpted it's easy to reduce or add fat layers.
After I sculpted the secondary forms I began the skins wrinkles and creases. I find what works best for me is to start laying in directional lines using the Standard brush for the wrinkles. Once I'm happy with the general flow of the wrinkles I use the Inflat brush in between them, and finally I clean it up with the Pinch tool. The finishing touch is to use alphas to add more detail or enhance the details I have already sculpted (Fig.01). I rely very heavily on photo references for this stage. Wrinkles go in certain directions on the face and to make them believable it's best to follow reality.
Once I was happy with the model I took a medium res version into Maya and used NexTools to retopologize. This isn't a necessary step when modeling for a still image but I felt it was good practice and I wanted as much geometry on the face as I could get. I then took the retopologized mesh back into ZBrush and re-projected.
I created the gun entirely in Maya. Although ZBrush has some awesome Hard Surface tools now I still find it much easier and faster to create certain hard surface elements within Maya. Before I exported my medium res version of the Tribesman for render in Mental Ray I transposed his arm to hold the gun I'd created. The modeling process for me is usually the quickest stage, especially if I take the time to find nice reference images.
Using ZBrush I baked out a 4k normal map for a mid res version. I used the mid res version for renders rather than the low poly with a displacement. I find that it renders faster without using displacement and if your computer can handle the larger poly count Maya scenes then why not.
For the skin texture I used 4k camera projections then baked the projection to texture. Using this technique allowed me to create a corresponding 4k bump map with a 100% registry. I used the Mental Ray fast skin shader to achieve the subsurface scattering and for a more realistic skin result (Fig.02). I made sure to account for the opacity of the paint in the epidermal weight map and as well in the bump so it didn't appear to be a part of the skin but rather a thick dried paint (Fig.03). For the skins weathered look I combined two maps. In the skins bump slot I hooked up the bump map and then attached the normal map's bump node to the bump node from the bump map. By using this technique I was able to keep the wrinkles I'd sculpted in ZBrush as well as the bump created from the texture map (Fig.04). I also used the mental ray fast skin for the horns in order to achieve the subtle hollowed effect. From there it was a matter of tweaking values to achieve the look I was going for in each shader.
To achieve nice soft shadows and realistic lighting I used a HDRI in the image based lighting node. I then placed area lights for some rim lighting and to brighten up certain areas (Fig.05). I used Photoshop for post effects such as scratches and color correction to give the image an aged and worn look.
From start to finish the project took about a month to create during my last semester at school. The canvas print translated well from the 3D image and now graces my living room. I encourage anyone creating an illustration to look into printing options. Having your 3D art hanging up in your apartment or house is just plain sweet and people will always ask how you did it!