I always manage my work as a pipeline; I set a direction to follow and I stick to the rule until I finish every face of the project. For instance, I don't shade my model if it's not completely done. To start another level of the job is distracting, so it is important to keep my attention and efforts always pointing to my north.
Let's paint the model... Good UVs give you good guides for your textures. In order to unwrap my geometry as best as I can get, I combine Headus UV layout plus the regular UV texture editor tools available in Maya (try the new interactive smooth UV tool, it works great). The texturing process was again based on more or less 120 pictures I collected. It was very important for me to portray the real car in high detail, so I made all the logos, titles in the cables, decals, dials, tags and stickers that every object required. I even painted some chalk writing on the tires, dirt and scratches here and there to get rid of the CG look that sometimes is too perfect.
For the rendering process, I used Mental Ray Image-based lighting. The reflections, light and color are coming from a HDRi picture set I recently shot in Vegas. I placed a chrome sphere within my mentalrayIblShape node to test my settings (be sure the reflections are facing the right direction). I used the camera tools I mentioned before to match my car and the back plate shot in terms of perspective and size. The result I achieved is coming directly from MR, I didn't make passes or compositing. Finally, I added some post production enhancement and color correction using Adobe After effects.
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