Screen Space Local Reflections (SSLR)

You can create a reflection effect using materials or other tools, but it is very difficult to do. Especially if there are many objects in the Scene that should self-reflect in each other. In addition, they also may have different degrees of reflection.

SSLR is applicable to flat surfaces, such as puddles or metal surfaces.

This post process works with objects that have PBR materials. For such objects, we set a certain value of the Roughness parameter (you can read more in the Materials).

The value of the Roughness parameter directly affects the result of using the SSLR post process. By enabling SSLR, you will see a reflection on flat surfaces to which the PBR material is applied and the Roughness parameter is set. The lower the value of this parameter, the clearer/sharper the reflection is.

SSLR has 2 parameters: Offset and Fade.

Offset

Offset is used to simulate full reflection. With the Offset parameter, you can determine at what angle objects should be reflected on a flat surface.

When offset is 0.1, the reflection occurs from the angle of total reflection. As if the objects are standing in front of a mirror.

And when we increase this parameter, the angle of reflection changes. After some time, the angle of reflection will be such that the reflection will disappear completely.

Fade

Fade simulates the attenuation of reflection on flat surfaces.

For example, a lunar path on the water surface. When the sea is agitated from the winds, the lunar path practically disappears and turns into a collection of flashing glare randomly scattered on the surface of the water.

The further into the distance we look (at the lunar path), the more clearly we see the moon, which is reflected in this path. Аnd if we look at the section of the lunar path that is closer to us, we just might not see the moon at all. Fade will help to create the effect of blurring reflections on flat surfaces.

All post processes can be combined and used to achieve the image quality we want. Using post processes, you can make the picture more artistic without using materials or other tools. But at the same time, you do not reduce the performance of your game.

Therefore, experiment and find out what is best for you and what you like best. There are no correct answers and mandatory parameter values, it all depends on you and your preferences.