3. Materials, lighting and rendering
The only textures I needed were the front tire maps. The other surfaces were made very quickly. The car paint had some very simple falloff map and the chrome was a fully reflective basic material. Around the car I put a sphere, that had some simple blue and brown gradient as its material. This worked as a reflection map for the chrome.
I also rendered a different reflection pass with scanline renderer, so that I could emphasize the outlines of the car nicely. For this pass the whole model had a fully black and reflective Raytrace material on it. It had a output map in its diffuse channel to add some intenseness to the reflections from the reflection planes.
For the beauty render I used one VRayLight. In case you're interested in rendering with Vray, I recommend the tutorials in http://www.aversis.be
I wanted the final version of the image to be 8000 pixels wide. Vray didn't handle that big resolution without crashing, so I decided to render a couple of 4000 px wide region renders of the image. I had to scale and set the images on top of each other in Photoshop afterwards, but I'm satisfied with the result.
The reflection passes I just rendered in 4000 px and stretched them to the full scale afterwards. That worked fine.
Finally I rendered an ambient occlusion pass to give the car some solidity and contrast. I think Vray would handle this task nicely, but since I didn't know right away how, I used Mental Ray.
Compositing is definitely the most difficult phase to explain. That's because I tend to be very experimental in this phase. Sometimes I might try to render the image with some very bizarre looking materials and test how they would seem in Photoshop's different blending modes and filters. Rarely it leads into amazing results, but positive accidents have happened. And sometimes I paint so much on top of the image that no-one could guess it was a 3D-image in the first place.
However, the basic approach of mine in compositing is to have the beauty render on the first layer, then on top of that the ambient occlusion pass in multiply blending mode and on top of that the reflection passes in screen blending mode. You can easily erase the bits in the reflection that shine too brightly or don't look good.
Then, I make the background for the image and finally I paint on a new layer a lot of stuff to cover the faults of the image. Some lamp flares, sparkles, dirt and ornaments on metal and paint surfaces and some smoke coming out of the pipes. About everything you think could improve the overall result.
For final touch you might want to put a black layer on top of it all and add a noise filter on it. Then reduce it's opacity to something like 10%. This method prevents the most intense spots of the image to pop out too aggressively. Like a very dark black area or a bright flare.
Finally, it's ready.
Only thing I regret is the fact I didn't make the car chassis in a bit more dynamic and curved pose, more like an animal in a jump pose. Now it is a bit too stiff and static. But that thing aside, I think I succeeded quite well with this piece.
Thank you for reading the tutorial, and thanks for 3DTotal for featuring my image J