Besides lighting adjustment, object reflection is also a key point in 3D game. There is a default reflection option called “Reflection Probe”. However, when using HDRP, means you can choose another powerful tool that better and stronger than simply using reflection probe, which is Screen Space Reflection.
Base of reflection probe
Before we using screen space reflection, first we still need a reflection probe to enable reflection in game.
Add a Reflection Probe from Light> Reflection Probe in Hierarchy.
This would create a sphere in scene with a wired square area.
Adjust the size by changing the value from Inspector to cover the whole game scene.
And you should see the whole game scene got reflection around now. You can also check the result when selecting reflection probe and check the material view in the Inspector.
Now the basic reflection, we can move on to enable the powerful tool of HDRP.
Enable Screen Space Reflection
The first thing to start using screen space reflection is enable it in Project Setting. Go to HDRP section and find the option under Reflections.
Or you can open this option window from Project> Settings> HDRenderPipelineAssset.
Check both Screen Space Reflection and Compress Reflection Probe Cache, then you should see the difference immediately.
Now the game scene has a much more accurate reflection. Quite accurate but not perfect. We can do some adjustment to make this reflection more close to perfect.
Add an Screen Space Reflection override in Global Volume.
Enable all, then make some change to everything to present a better reflection.
Now you can create a nearly perfect reflection to your game scene.