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Skill Level Beginner
- [George] Hi, I'm George Maestri. If you want to control the overall lighting of your scene, you need to learn a bit about Auto Exposure in Unreal. Now, Auto Exposure automatically adjusts the lighting in your scene so that it's an acceptable quality. Now, sometimes you'll want to change this to get a certain effect. Now, we can do this through Auto Exposure. Now, the easiest way to control Auto Exposure is to simply toggle it on or off. So, if we go into our Project Settings, we can search for Exposure, and you should find it under Rendering Default Settings. So, the one we want to look at is Auto Exposure, so if we turn this off, notice how the lighting in the scene changes basically subtly. Now, depending upon the scene that you have, it may change dramatically or subtly, and we can also control how Auto Exposure is calculated. Now, the one thing about doing it in the project is that it controls it for everything in the scene. So, if you a number of different levels, as we do, you will have this control turned off for everything. So, it's probably better to control it on a level-by-level or scene-by-scene basis. So, in this particular level or scene, we can control it using a Post Process Volume. So, let's go into Volumes, find Post Process, and drop a Post Process Volume in there. Now, in order for this to work, we do need it to be set to Infinite, so if I type in inf, you should have Infinite Extent or Unbound. Make sure we click that on, and now that affects everything. And then, let's X that out, so let's go ahead and search for Exposure. Now, we'll find it under Lens, so this should be the top rollout here. So, under Lens, Exposure, we can turn on Exposure Compensation. Now, Exposure Compensation takes our traditional Auto Exposure and then just adds or subtracts light to it or basically exposure. We're not actually adding light. We're just letting more light into the lens, so if we turn this up to say seven or eight, you'll see that the scene starts to get really over-exposed and blown out. Now, we can turn it down. If we go below zero, we darken the scene, so in this case, at negative three, it's fairly dark. So, this can be used to fine-tune the lighting in your scene. So, if you go from level to level, you want to make sure you have a consistent lighting. Or, if for some reason you want a scene to be a little bit darker to get a certain mood, you can do that, as well. Now, by default, this should be zero, which is exactly what the Auto Exposure calculates, so anything above zero adds exposure or basically makes it brighter. Anything below zero makes it darker. Now, if we want to, we can control this a little bit more effectively by controlling the Minimum and Maximum EV values. So, the Minimum EV value if we dial that up, it will tend to darken the darks. The Maximum if we bring that down, it will lighten the light parts of the scene. Now, typically I keep that where it is. Now, if we want to, we also can use a texture to really control how Exposure Compensation works over the scene. But as you can see, it's very easy to control the overall exposure and lighting in your scene by using a Post Process Volume and controlling exposure.