Follow Andrzej Sykut's series on Lighting La Ruelle outdoor illumination with chapter 2: Sunrise/Sunset...
Before placing a single light in a 3d software, it's good to spend a while, looking at the scene, and thinking, imagining a bit. The assignment is pretty clear - sunset/sunrise - that's the 'prime directive'. But that is not all that matters. Composition of the image is important, regardless of the lighting scenario we have to achieve - and that too can influence light placement, strength and color. Visual style, art direction is important as well - is it supposed to look real, photo real, stylized? Finding some reference can suggest few ideas, how to achieve our task. It's also good to think about technical aspects - is it going to be a still image, or is it for animation, should it render really fast, or maybe we have some computing power at our disposal? But nowadays, when the computers are fast, it's not always that important.
So how does all that theory work in real life case? Well, there are two most obvious (and easy to recognize) ways of showing a sunset. In the first one, the sun is behind the camera. The shadows of the buildings, especially off-screen ones, can become a very important element of the scene. Because there are parts of the image in warm sunlight, and some in the cooler shadows, there can be quite a lot of color variation (Fig.01), and the contrast isn't very high. Second approach, we are looking at the sun - there's a lot of bright light, things are shiny (because of the glancing angle of the sun rays), there are nice, long shadows, and the overall contrast can be quite high, but there can be little in a way of color variation (Fig.02). Both ways differ in mood quite a bit - of course, you can choose somewhere in between - it depends on the scene, and on the story you want to tell.
There are similarities, too. In both cases, sun is our main (key) light source. Sky acts as a fill - but the ratio between the two is different. This looks like a great candidate to use Vray Sun&Sky system as a base of our light setup, at least at first glance. While it should work for the first scenario, it may not be flexible enough for the second one - in that particular scene. The arch at the end of the street blocks the horizon, (Fig.03, marked red) and whole scene would be in shadow... unless we try something else.
Let's start with the first approach.
To render the scene, I'm using 3dsmax with Vray, with GI turned on. I most often use Irradiance Map for first bounce and Brute Force for the secondary bounces - that is the default setting, which works for me in most cases (Fig.04 - preview setting). Detailed settings, like number of bounces, or Irradiance Map size of course vary over time - low quality for previews, higher for final rendering. For still images, as in this case, I try to use fastest (lowest) setting possible, while still getting acceptable result. For animation, the Medium Animation setting is usually safe, flicker free option. I also use a hint of global Ambient Occlusion to add some detail to shadowed parts of the image.
Next thing I did was setting the Color Mapping to Exponential (Fig.05). While this isn't probably the most physically correct way, it has some advantages. The way it works, it prevents overbright 'hotspots', and oversaturated color transitions. It's also very tolerant - it's really hard to whiteout the image, and the lights have a very wide range of usable multiplier/strength setting (but that range often ends up being pretty high, like 512 or so, especially with the fog on). It has downsides, too, making the colors look desaturated, and decreasing the contrast of the image. I actually like it that way, because I can easily bring back the contrast and saturation in post production, and for some scenes it just fits - but if you don't like it, there's HSV exponential mode, which keeps the colors better. Generally, though, main use I have for default, Linear Multiply, is rendering some additional passes, like masks.
Then, I've set up the road surface (Fig.06). A simple Vray material, VrayDisplacement modifier, and we are good to go. I also added some reflections to the windows (using blend material, VrayMtl for the windows, and a b&w mask). Metal parts, like railings and lamp also use shiny, reflective VrayMtl.