Post-production might well be the most underappreciated part of creating 3D visualizations. It gives you the power to easily make some changes; put in the sky you like, add some dirt, make the colors more vibrant and even correct some little mistakes in your 3D mesh.
Most of the traditional 3D artists tried to do as much as possible wihtin their 3D package since these packages were not focusing on post, but rather on the 3D products themselves. Rendering masks for the different color corrections one would like to do was a painstaking job of fixing the lighting and materializing — making artists choose to do most of the work in 3D (such as adding dirt and textures) and so leaving only color correction for post-work.
The techniques and styles of correcting images in post-production have changed a lot over the last couple of years. First, we shall take a look at some of the trends and techniques that are happening right now. Next to that, we will take a look at the most impressive architectural visualization shot that CGI has ever seen and at the post-production in that shot. Next to that, the trend it started in terms of post-production.
Different Styles of Post-Production
This is what a 3D image should look like according to the corporate industry. Basically, what you do is the following: take a render, do some minor color correction and add some glow. Despite the fact that this is mostly considered standard, it should belong to the past. There are a lot of techniques out now to create better looking, more beautiful images with the help of post-production software. Let’s look at some examples.
This image, created by a Dutch company called “Trazar” explains exactly what the “standard” is. The image looks great and a client would absolutely love it because the building is so clearly visible, but it looks too perfect. So to a 3D specialist, it still looks fake.
Some things that immediately come to mind:
- Everything is completely balanced; you can see the sky clearly (it is not too bright), but you can also see every little detail in the shadows.
- There is a blank spot at the horizon, which is odd, because it’s situated in the middle of a city.
Here is another example, made by a company called “Archiform”. This render too looks very realistic, but still doesn’t look quite as good as it could with some heavy post production.
Same thing here:
- The colors are too vibrant.
- The glow of the sky makes the trees blue
Degraded photorealism
A synopsis to explain what I’m talking about: “Degrading your images in post with scratches, vignetting, lens blur and many more things, making your image look more like a photo taken by a (bad or old) camera that uses film rather then a 3D render”.
What we make in our 3D packages can look perfect: our edges can be exactly 90 degrees (or 89 for that matter), our tabletops can be completely clean without dents in them, as well as that we can produce images in low light condition with an ISO of 6400 without a single drop of grain in the final images. This technique focuses on how to overcome the perfectness of 3D. It is unmistakably the most popular post-production trend at the moment used in non-corporate 3D visuals.
Let’s look at the only example needed to illustrate this technique. This video is made by Alex Roman, a 3D visualization expert.
Now, the thirst thing that’s noteworthy is that everything except the people and the birds is 3D. The art of 3D visuals has come a long way and if we would give a good 3D artist one year of free time on his hands to make whatever he wants, this is what he would come up with (at least, “Alex Roman” did).
Alex Roman’s “The Third & The Seventh” shook-up the 3D world by using a great cinematic style to make the architecture stand out. Most of the time, you don’t even realize it’s 3D.
So, what part of this is done in his 3D package, and what part is done in post? To let Alex answer the question himself, here is another video of the compositing breakdown. He shows a wireframe or smooth shaded view of the model inside 3D studio max, after that the bare render. Each next frame includes a new step of post-production.
As we can clearly see he replaced the sky, added people, corrected the color and added some other visual elements in post. Those things are purely decorative. What really sets the mood, is the use of vignetting, lens flares and lens blur. He makes it look like this was a movie shot in the early nineties. Don’t get confused, it is not only the post-production that made this mood happen (cameramen wearing somewhat classic clothing etcetera), but this is certainly something that helps a lot! This movie would have been completely different if it hadn’t been corrected in post.
Lets discuss how we can achieve this effect, and look at the stuff that will work, and how the same stuff, applied in a wrong way, won’t work. In the examples below, these effects have been exaggerated to better see the difference. I’ve had to limit myself to a couple effects since it is simply too much to discuss all of the techniques I use. The ones I’ll describe below should get the basics though.
Large view
When using old camera’s with film, there very often is some grain in the darker areas of the image because the film won’t pick up the details in the darker part of the image. This effect can be easily achieved in our post-production package. I used photoshop here.
Do:
- Make the effect barely visible, only noticeable if you look good.
- Use plugins like “NIK color effects” that can simulate actual grain from a certain film. This will boost the credibility of the grain.
Don’t:
- Add noise in brighter areas of the image, this will look unrealistic.
- Overdo it. Some noise is good, but don’t make it disturbing, the end product should still look good.
Large view
Vignetting can have different causes in photography. The main cause is using a cheap lens / camera. Most of the time this effect is unwanted, but sometimes it can create an image that centers your eye, or guides it to a specific part of the image.
In post, we can use two types of vignetting, one brightens the middle of the image, the other darkens the edges. Normally, the last one is used, since the 3D render still has to maintain it’s function of showing the subject properly, when it’s too bright, this isn’t always possible.
Do:
- Add vignetting to your renders! It looks cool.
Don’t:
- Tell your client about is, they won’t like that you are degrading otherwise perfect images just too make them look cool. If you use this effect moderately, they probably won’t even notice.
- Overdo the effect. This will make your image look very dark, and might not fit it’s purpose.
- Add them when you are rendering studio setups and such. The effect needs to be believable. Studio camera’s are often setup to not have vignetting, so when applied in this case, it won’t look re
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