Unreal Engine 4 Shaders and Effects Cookbook: Over 70 recipes for mastering post-processing effects and advanced shading techniques

As you probably already know, Unreal combines many different pipelines in order to create whatever it is you are after—a video game, an app, an architectural walk-through. From animation to rendering, there are many different fields of study that we could be looking at. However much we would like to do so, the topics are just too wide to be tackled here. But even though we are not going to be looking at all of them, there is one important aspect that we need to pay attention to. It is one that directly affects the material and the rendering pipeline—we are talking, of course, about post-processing effects.

At their core, post-processing effects are a rendering pass that happens after our materials have been constructed but before the whole scene is outputted to the screen. They are like a layer that we can insert between what we have created and what the user experiences, so they are very powerful tools that enable us to modify and correct what we have previously done. Throughout...

In order to access the different post process effects that Unreal has in store for us, we will need to place a specific actor in our level. This actor receives the name Post Process Volume, a container in the shape of a box that specifies its area of influence.

Thankfully for us, every setting that we are going to be tweaking in this chapter can be modified using the previous actor. Having all of the post process effects grouped in one place makes our lives easier—so, let's start looking at all of the different options that we can play with!

After we've taken some time to familiarize ourselves with the post process volume actor, it is now time to start looking at how to use the different functionalities we can find within it.

The first section that we will be covering is also the first one we can find if we look at the details panel for the actor and that is the Color Grading tab.

The reason these options exist in Unreal is similar to why they exist elsewhere, like in movies or videos. The end goal is to provide artists with a series of tools that they can use to alter the look of the final image. Similar techniques have been prominent in motion pictures, for example, where the captured footage is adjusted to satisfy a particular need be that the establishing of a stylized look or the ensuring of color continuity. What we are going to be doing in the following pages is exactly that tweaking of the default camera values to modify the look of our scene.

In this short recipe, we are going to take a break from the post process volume actor to focus instead on the Cinematic Camera one. That doesn't mean we are leaving behind the world of post processing effects, far from it, in fact. The beauty of this recipe resides partially in learning that the previously used post process volume has a companion in the shape of this handy camera. Both of them have access to some of the post processing functionalities that Unreal offers, and learning when to use each one can be quite useful.

The other part that we want to cover as well is the setup of a proper camera, pretty much as we would do if we were working with a real one. This is especially useful as some of the most used visual effects we can introduce directly relate to this actor, so it makes sense to master it before moving forward. 

We took some time aside in the previous recipe to learn about the other type of actors that have access to the post processing effects in UE4 – the cameras. In particular, we focused our attention on the cine camera actor, a specific type that has the potential to use certain cinematic effects. Taking it from there, we will continue to look at some other cinematic techniques available to us while still using that same camera actor. We'll take a look at Grain, Vignetting, Chromatic Aberration, and more. 

The reason we continue to use a camera and not the post process volume is because some of the effects we are about to include come from the world of cinematography. While they definitely can be used on the volume as well, it does make sense at this stage to continue to use the camera if only to just replicate how things would also be happening in real life. After all, Unreal bases much of its capabilities in the realm of reality, and these are another...

The post processing effects that we are going to covering in this recipe are going to deal with lights. Daily life has probably taught every one of us about the different consequences that light introduces in our vision: as in what happens when we look at a very bright spot or how our eyes adapt to sudden changes in lighting. If you have also dealt with a camera in the past, the chances are you've also seen how certain camera effects can start to show if we have a light source in our sights. This is what we are going to be covering in the following pages: namely, two of them known as Bloom and Lens Flares. Replicating those effects in Unreal is easy and can add a bit of flavor to your scenes, as long as they are use in a subtle way. Let's take a look at them!

Welcome back to another recipe on post processing effects! I'm quite excited about this one, as we are about to start creating our own personal effects instead of using the ones we already have available through the engine. To do so, we'll take advantage of a particular type of shaders called the Post Process Materials that, to be honest, are quite self explanatory. They are the ones to be used when we need to adjust the scene as a whole. They are applied inside the post process volume, and not on a particular 3D model. Because of that, the way we create them is somewhat different to that of a standard material, so we'll be taking a look at how they are structured. This recipe will be the foundation which will let us create more complex effects later on, so let's jump right in!

Welcome to the last recipe of this chapter! So far, we've had the opportunity to play around with most of the settings that both the post process volume and the cine camera actor have to offer. We don't want to say goodbye to this topic though without looking at some of the final technical adjustments we can perform on our scenes at a global scale. That being the case, we will focus our attention now on several important values such as the following:

All of the previous topics are often viewed more from a technical point of view rather than an artistic one. They can have a great impact on the visual quality and feel of the scene, and we don't want to downplay the part that they have on that regard. However, more often than not, they are values that we have to adjust keeping in mind the performance that we are after. It's not so much a question of whether we want...