Intro to Post-processing

Post-processing is a non-destructive way of defining the overall look of the whole island or only part of an island by using placed volumes in Unreal Editor for Fortnite (UEFN). Post Process Volumes include settings which can affect lighting, scene coloring, add camera effects, and more. These can affect how the island looks and add visual interest.

Post-process volumes (PPV) will help you push the look of your lighting further if you are developing for several platforms. PPVs will have an impact on the number of variables you have to keep track of for consistent looks throughout the gamut of low-end and high-end devices, as not all devices support all features and post effects.

Let’s begin by exploring some industry lighting and post-processing terms to better understand what effect you’re using and how you’re using it in your project. Below the list of terms is a tutorial that teaches you how to use the Post Processing Volume to create a cinematic effect.

Learning Post-processing and Lighting Terms

These are some terms used with lighting and post-processing, common across gaming, media, and computer graphics industries concerned with capturing images.

Knowing them will help you understand what you’re trying to achieve when you’re creating your lighting and post-processing effects. You can even apply these terms to other industries that are concerned with capturing images, such as film and photography.

Contrast

Contrast describes how highlights transition into shadows. The brightest areas of the image are the highlights. The darkest areas are the shadows. In between, the image will have lights, midtones, and darks.

Saturation

Saturation describes the amount of brightness a color appears to have on an island. In Contrast, lightness tells how dark or light a specific color is. Color saturation can mute colors which yields a grayscale or black-and-white appearance, or it can over-saturate a specific color or range of colors making them more vivid.

Value Saturation

Enhances the contrast between two of the three RGB values. With Lumen Exposure, you can achieve uniform saturation in your project.

Direct Light

Direct lighting is any lighting that comes directly from a light source such as a light bulb, flash light, and the sun.

Indirect Light

Indirect lighting is any light that comes from a direct source but through indirect means, such as lighting bouncing off objects in the world (walls, rocks, etc.), or an overcast sky, and places like the shade of a building.

Occlusion

Occlusion refers to blocking, when an object blocks light. It wouldn’t be wrong to say that all regular shadows are kinds of occlusion, but the term occlusion really refers to other kinds of light-blocking that aren't regular shadows from a light.

Ambient Occlusion

Ambient Occlusion is a post-processing effect that approximates crevice shadows in real-time, darkening creases, holes, intersections, and surfaces that are close to each other. This gives a more realistic appearance to parts of objects where ambient light is blocked out or occluded.

Dynamic Light and Reflections

Dynamic lights simulate different kinds of light sources. There are a few different types of control options for dynamic lighting: warm dimming, color-tunable, and color changing.

Dynamic reflections are a quality level of reflections from given light sources. Lumen handles the shadows and reflections once you add the Lumen Exposure Manager to your project. The manager allows you to edit occlusion, contrast, and saturation to create a richer experience.

Think about the lighting in Fortnite Battle Royale Chapter 4, that’s what you can achieve with dynamic lighting.

Color Grading

Color Grading is the process that alters or corrects the color and luminance of the final image. You can also think of Color Grading as the process of altering and enhancing the color on your island to give it more emotion by creating stylized and aesthetically pleasing scenery.

It’s a lot like when you apply a filter to a picture you post on social media. In this case Color Grading tools included in the post-processing stack use the tone mapping features with HDR to color correct the processing of images.

For additional industry terms, refer to the Lumen Exposure document.

Creating Cinematic Effects

Post-processing is used across media to add filters and effects to image, film, and video games. By using a Post Processing Volume on your island you can create an effect that adds to the drama of the island and how players feel when playing on your island.

In this tutorial, you’ll learn about the relationship between materials, lighting, and post-processing by changing your scene lighting settings, tweaking visuals, and post-process settings.

1. Create a project using a template pre-populated with assets.

2. Select Actors > Visual Effects > Post Process Volume. A box appears in the viewport, this is your Post Process Volume.

   

3. Select the Post Process Volume in the Outliner to open its settings in the Details panel.

4. Toggle on Infinite Extent (Unbound).

   

5. Set Priority to 10.0.

   

6. Expand the following settings and toggle them on:

   1. Color Grading

   2. Exposure

   3. Chromatic Aberration

   4. Image Effects

7. Expand the Color Grading effect Global and toggle on Gamma.

8. Set the RGB settings to the following:

   1. R = .75

   2. G = .85

   3. B = 1.0

   4. Y = 1.0
      

These settings give the scene a blue tint.

1. Expand the Exposure settings and set Exposure Compensation to 1.5. The viewport scene gets brighter.

   

2. Expand Chromatic Aberration and set Intensity to 1.0. You should see some color separation, especially at the edges of the screen.

   

3. Expand Image Effects and set Vignette Intensity to 1.0. The viewport should darken around the edges.

   

   You can toggle the Post Process Volume visibility on and off in the viewport from the Outliner to see the difference between using the volume and turning it off.

   

Using a Post Process Material

For the second part of this tutorial, you will create a material to use with the Post Process Volume that changes the look of the scene to black and white.

For more information on creating materials, refer to the Materials section of the UEFN documentation.

1. Create a folder in the Content Browser called Materials. Then double-click on the Materials folder to open it.

2. Right-click inside the folder and select Material from the dropdown menu. Name the material PPV_Material.

3. Double-click on the material thumbnail to open the Material Editor.

   

4. Change the Material Domain setting to Post Processing.

   

5. Add the following material nodes to the material graph:

   1. Scene Texture node

   2. Desaturation node

   3. ScalarParameter node

6. Select and expand the Scene Texture node, change the Scene Texture ID to PostProcessInput0 from the dropdown menu. This applies the material to the post-process scene.

7. Drag off from the Color output on the Scene Texture node and connect to the Desaturation node’s input. This desaturates the look of the applied material by the value applied to Fraction Input.

8. Change the ScalarParameter node’s value to 1.0 and drag off from the output pin and connect it to the Fraction input on the Desaturation node. This desaturates the look of the applied material by the value applied to Fraction Input.

9. Drag off the Desaturation node’s output pin and connect to the Emissive Color input on the Main Material Node.

10. Click Apply > Save.

    

11. Return to the main viewport and select the Post Processing Volume in the Outliner.

12. Expand Post Process Materials under Rendering Features and click the plus sign to add an array.

13. Click the dropdown menu and select Asset Reference.

    

14. Click the Array dropdown menu and select the PPV_Material you created.

    

The scene in your viewport should now have a black and white filter applied, driven by your post-process material.