Why are Screen Space Reflections Unique in Unity?

Objective: To understand what Screen Space Reflections are and how they can enhance the quality of your scene to give it a more realistic feel.

This is a feature in the High Definition Render Pipeline (HDRP) that provides subtle reflections onto surfaces that can simulate puddles or wet floors. It even has the added bonus of reflecting both static and dynamic game objects which can help build a super realistic scene.

Continuing to build onto our Sci-Fi lab room, we have a few floor panels that don’t have much reflective quality to them in the middle of the room, so let’s add some SSR to the scene.

To get started this is going to be our base floor surface that we are going to build our reflections into and we will use this to compare the added SSR:

First step, let’s add a Reflection Probe to the middle of the scene, right click in the Hierarchy → Light → Reflection Probe and adjust it’s position so it is sitting in the middle of the room:

Next, make sure to adjust the Box Size on the X, Y, Z coordinates so that it encompasses the room and let’s also tick the box in the ‘Projection Settings’ called ‘Use Influence Volume’. If we don’t have this ticked it is going to use an infinite reflection probe of our environment and we want it contained to within the box.

From here we need to dive into our HDRP Asset which you can find in your Project window by simply clicking on Edit → Project Settings → Graphics → Scriptable Render Pipeline Settings, and simply click in the box and it will take you to the asset in your project files.

It’s time to switch on ‘Screen Space Reflection’ by ticking the box under the ‘Lighting’ tab:

One of the final steps is to add the Post Processing override ‘Screen Space Reflection’ and to do this head to your Global Volume game object → Add Override → Lighting → Screen Space Reflection.

IF you are stuck here and your Unity project is giving you this error:

Then the solution is to open your ‘Project Settings’ → ‘HDRP Default Settings’ and make sure ‘Screen Space Reflections’ is ticked:

You also need to make sure that the ‘Low’, ‘Medium’ and ‘HighHDRP Assets also are all ticked (This is where I was going wrong and only had the ‘HDRPHighQuality’ SSR ticked):

We should now be error free! Let’s head back to the ‘Global Volume’ → ‘Lighting’ → ‘Screen Space Reflections’ and we should have this screen where we can tick ‘All’ and start playing around with the options:

These are the settings I have changed to achieve this beautiful result!

Screen Space Reflection Settings
Screen Space Reflection in conjunction with a Reflection Probe

Passionate Unity Game Developer