It was important to get the AO (Ambient Occlusion) right before texturing the model as it would assist in the spacial mapping of the model in 2D space when I am painting in Photoshop. Sections of the model that intersect (such as the backpad with the main body) would require lots of little tweaks and changes if I hadn't used an AO map, due to the differing scales of items within the UVW Unwrap and rotational alignment of the seperate elements it helps dramatically to understand the arrangement of the model in 2D space.
My process for creating the AO map is slightly different to the conventional process, I like to use a combination of Global Illumination with a low stochastic sample and the in-built Ambient Occlusion texture (both exported as seperate textures and combined in Photoshop). This seems to give a smoother finish, bringing a slight 'grain bleed' to the model which makes the shadows appear slightly more realistic.
I also ensured the arms were seperated from the model at a reasonable distance so not to catch shadow on the underside of the arms; otherwise if the robot were to be animated and lift its arms you would see a pre-baked static shadow of where his used to be.
Below is a render of the model with no lighting or shading within the scene, simply an unlit texture using the AO texture applied through the multiply channel.
Ambient Occlusion map
The normal map for the robot was purposefully made to have 'hard' edges, I wanted the light to catch the manufactured edge of the cylinders that make up the robot. I think it works but normal maps and height maps are something I definitely want to understand the theory of next year, from a selection of articles I've read so far it appears a combination of both height and normal maps are what add the realism (and not so much used independently).
