Since my goal was to create a single artwork, I could have cut some corners and simplified the whole texturing process by using techniques like camera mapping. However since I work as a character artist in a games studio, I also wanted to hone my skills in traditional UV texturing. As I was aiming for a realistic look, I had to use photo references as a base for the textures. Using Photoshop I matched several high-resolution photos of Obama from different angles, i.e.: from frontal to 3/4 to profile views.
The first thing I had to do was get rid of every shadow and every specular highlight on the photos, so that in the end I had a solid diffuse color map. To achieve this, I painted masks on Level and Hue/Saturation adjustment layers, and even performed a Select > Color Range and filled up a selection with a solid color (Fig.05).
The second task was to match the different photos using more Level and Hue/Saturation adjustment layers. To blend the photos into each other, I gave them each a layer mask that I painted to add or remove their visibility (Fig.06).
In order to make the whole fit to the UVs, I used Liquify and the stamp tool. Unfortunately finer details got lost in this process, so sometimes I had to use the Healing Brush to grab details from an intact zone to a blurry zone. At points like this it's important to respect that skin pores and wrinkles are quite different in the various areas of the face, i.e.: nose pores are not like forehead pores.
The next mission was to paint details and highlight areas like digital make-up. This was done especially around the mouth, eyes and the hairline.
Finally, I created a specular map and a bump map (Fig.07). The latter was used on top of the ZBrush displacement map, in order to reinforce the diffuse map and create the skin pores.
Once the textures were done, it was time to start some rendering in Maya. For lighting setups, I tend to follow the Occam's Razor principle and use as few lights as possible (Fig.08).
The right side of the image was deliberately kept darker to add a particular mood. I used an HDR image as an Image Based Lighting environment for my reflections. When adjusting the lights and reflections, I just had a basic lambert or blinn shader on the model (Fig.09). Once my lighting was set and I started working on the SSS skinshader, I tried not to tweak the lights anymore as that would unbalance all the shaders.
As you can see from Fig.10, I used Mental Ray's misss_fast_skin_shader with some reflection. I ended up not using any G.I. or Final Gathering, since they didn't provide noticeable results.
For the hair, I duplicated the head polygons where the hair would appear and applied Maya Hair. Â You can see the settings I used in Fig.11.