I used an Ambient Occlusion map (AO) to get that dirty and the old-looking texture for the materials, and also to achieve a sense of depth (Fig.10).Â Â Â Â
It's very easy to obtain a good AO map if you have unfolded the UV coordinates correctly and you have prepared the scenes before. I rendered to texture with each object using Mental Ray, and the steps I took were as follows:
I hid all the geometry elements that could affect an AO map improperly - in this case, the planes behind the character
I added an activated skylight in the scene without any other light (Fig.11)
I added an Ambient/Reflective Occlusion map from Mental Ray in the self-illumination map of a standard blinn material; I used these materials in the "material override" option of the render engine - Final Gather and Global Illumination were deactivated since the default options gave pretty good results (Fig.12 - 13)
By clicking on "render to texture" I created a map double the small size for texturing I was to use, rescaled it in Photoshop, and finally added a noise effect (Fig.14).
Fig. 12 & 13
Illumination, Render and Shader Parameters
I rendered the final scene with V-Ray because I find it to be a very easy and comfortable working tool. Its production results and speed are also the perfect choice for this kind of scene!
I usually do a fast illumination setup with the combination of HDRI and 3 lights. For Captain Bonecrusher I used a plane that surrounded the character, which allowed me to create more bounces of light over him (Fig.15 - scene light setup; Fig.16 - render parameters).