I split my final renders into several passes. It takes too much time and effort to create a single pass with everything tuned to perfection, and it's not versatile at all. Post-production is another fundamental process to convert a good render into a stunning image, but I don't create a huge number of passes if I don't need them. In this case I kept all the vehicle passes together, and I focused more on integrating the backplate with the CG elements. These are the passes I rendered (Fig.21).
During the lighting and compositing process I did some minor modifications in Photoshop to the backplates. This mainly involved removing structures and details that could distract the attention from the APC or make it harder to read the silhouette. The sky was extremely important to set the mood, so I spent some time trying to find one and retouch it (Fig.22).
This is the schematic view of my layer structure in Photoshop (Fig.23).
I am pretty satisfied with the results (Fig.24). I believe I maintained the original feel of the Combine APC, and I achieved a good degree of realism overall. Of course this work is far away from perfect; I could have worked on the model a bit in ZBrush or Mudbox to add details to the surfaces, or added a dust map to give some more detail to the surfaces. The glass on the roof is sparkling clean, but the underneath of the model is still quite rough. I'm not 100% convinced with the paint shader; I believe the vehicle is too shiny in certain areas, so I should have rendered the reflections on a separate pass and masked out some areas.
Anyway, I gave myself a deadline to finish this work by even If I didn't have to. There is always something left out in every work. In the end I wanted to improve my hard surface modeling skills and my capability of handling a complex asset like this one from the beginning to the end.
I hope you enjoyed reading through this Making Of and that the concepts I explained here are going to be useful for your own projects!