Exporting the file
As I said before, I can't explain all the steps in detail, so I'll give you quick overview on how I use NURBs to create the model. What I like about NURBs is that it works as it should in real life. Imagine you are in the Orange County Club, making choppers. You have big sheet of metal and trim it give it a shape, if you need holes, you just drill them. Everything in NURBS is the same as those real life actions, you just use commands instead of real instruments.
After I finished the model, I deleted one half and started to make objects from the model. I needed these to make the render easier. For example, I wanted all the tires to be one object so when I assigned a material to that object they all get the same material at the same time. Thanks to Michael, (he made this custom command for me) I was able to assign a unique object name to selected geometry and then hide them, so I could see which geometry needed to be assigned a name. After all the objects were hidden, I knew that all parts of model were named.
After that, I mirrored the model to get the symmetry and started to export it to OBJ for rendering. MoI has a great Export to OBJ function that allows you to control the geometry of the polygonal model in different ways. For example, you can control the polygons form and make it triangular, quads, or n-gons.
After it had finished exporting, I started the render.
This shows the model at this stage. I changed one or two details, such as the big rockets, and found it looked more attractive
Rendering light and UV maps
The idea for the render was to make the car appear very fresh and clean, as if it came directly from workshop. I didn't want any dirty areas, and wanted it to appear polished and shiny in a big production studio with a white background. I love this studio look, as I frequently worked in them during my career as a music video director. I thought the model would look great on white background because nothing would distract the viewer's attention from the car and it would look like a real studio environment.
For the rendering I used Cinema 4D. I like how the rendering part of this software is implemented - it's very simple and intuitive. For the background I used the Greyscalegorilla Seamless floor and the HDRI Studio Rig. This is little patch in the HDRI library that allows you to work with HDRI more easily.
I used very simple HDRI to light up the scene, and as you can see it's almost white. I wanted that white, smooth, and diffused light for the scene, so no other lights were used. For the background I used the Greyscalegorilla Seamless floor, but it can be easily replaced with objects that reproduce the white studio background.
I didn't create any kind of UV unwrapping, I just used the UVW mapping that Cinema 4D automatically produces.
Examples of the effects created with the lighting set up
All the materials on the model were very simple - nothing extraordinary. I like to make all materials from scratch, but some metals were created with custom textures I used from the Cinema 4D library. No additional textures were used, except some procedural noises that I made to make some parts look more realistic (these were standard noises with a big scale.
I very often use layer shaders when composing materials. One thing I learned from my render experiences is that simple doesn't always mean bad. I play with different colors, reflection, transparency and specular every time. It's important to remember though, that if there are no lights, specular doesn't work. Sometimes I'll add lights to produce a custom specular effect on different details, but I didn't use them in this case.
Using layer shaders to compose materials
Also I used procedural textures (or tiles) to make certain materials, for example those that you can see on the chassis. For the glass I used the standard transparency settings and played a bit with the Refraction index.
One very important thing to keep in mind is how close you want to show your model - if something looks good from a distance it can sometimes look bad when you see it close up. So, for example, the backlights on the car are just tiles with black and red quads, and it looks good from distance, but if you zoom in, it doesn't look so good. This rules works for every detail.
Making sure the procedural tiles work well at the distance needed
I used the standard render engine; I like this more than the ?physical' render engine. Standard is faster and I can't see a lot of big differences between them.
I always use Ambient Occlusion. I like it a lot and think that it's the first factor that makes a model look like it's from the real world. The AO settings in Cinema 4D allows you to increase the contrast of AO. I prefer to have the AO very noticeable, so I increased this value to 50%.
To use the HDRI lighting in Cinema 4D you have to turn on Global Illumination. I often make some tweaks to this parameter to reduce the render time. Here, in the Irradiance Cache tab, I changed the Record density of min and max to -8 (it's maximum). I can't see big differences when it's on maximum and on minimum, but the render time is dramatically different at 20 times faster.
I always render at 1600x900 if there are no special requirements from a client, because I don't like to spend a lot of time rendering very big images. The average render time for this model was 4 minutes.
Tweaking the render settings for a faster render
So that was my workflow. As you can see, I prefer to keep it as simple as possible; and everything has to be easy and fun. I use this workflow on practically all my concepts and models, though sometimes I start from a photo collage and others I start by drawing basic shapes by hand or sketching directly in MoI. I think the main thing is to create a good concept - the modeling and rendering are just tools to make this idea.
Views of the final image