Tone mapping

- Post processing effects in Unreal Engine 4 really bring our overall scene to life. These can affect the way our viewer views the game, whether it be with materials, lighting or the overall static meshes or games assets as they were. So, providing post process effects can really change the overall kind of theme or experience of the game. And we're going to take a look at how we can do that in a couple of different ways here. Now, one of the things that we want to address is this kind of concept of color grading in the game.

Now, if you're using any kind of HDR lighting or even any kind of global illumination, anything that's lighting-based off of an image. In this scene here we are using that. We're using the sky environment to provide a basic lighting environment. Now, a couple things that we can do in this scene, if we come up to the Show menu and we go down to Post Processing, you'll see at the bottom we have a Tone Mapper and if we look at the view port and we click that, we'll see that we've actually affected that in quite a different way. You see that the lighting is a little bit different.

We see that as we tumble around, we are getting these kind of more harsh lighting effects that are happening within the view port. What's happening here is that the view port is calculating the light from the direction that it's coming from, from the way that we've set up our overall source light and it's calculating that to the camera. So as we tumble around here we're going to see that lighting is quite dynamic and we can actually get a feel for it. If you tumble up and down, you'll see that overall tone kind of adjust on the fly as we tumble up and down and around.

So that's an interesting way to work overall with the color as it has to relate to the lighting within the scene but this can also provide different effects especially for different times of day. So tone mapping is definitely going to be a different kind of experience if you have something that's much darker and the light from that scene to the camera is much less pronounced. For much brighter scenes, we could even see more effect of having something like from out here for example where we're seeing it look very bright from far away and if I zoom in and just start to tumble back, we kind of get that effect of that darkening down.

So you can see that tone mapping really provides this different kind of overall lighting feel to the scene based off of your environment lighting, especially if you're using anything taking advantage of high dynamic range lighting.