Black Dragon Viewer Guide: #4 Screen Space Reflections

What is it?

Screen Space Reflections, just like Screen Space Ambient Occlusion is a screen space limited feature that aims to improve the visual quality by offering 'cheap' versions of otherwise highly demanding features, in this case full blown reflections. It's not perfect and brings its own set of issues but does a decent job of giving especially metallic surfaces a lot more realism. It does so by doing simple post process reflection calculations and aproximating what should be reflected and how much.

How does it look?

You can see that Screen Space Reflections aren't particularly realistic nor correct but they do a decent job of giving these metallic beams that extra bit of metallicness, the wall on the left and the beams in the roof also profit a lot from the reflections of sky and other objects inside the room. Generally Screen Space Reflections can massively improve the looks of virtually anything if the specularity is configured properly and normal maps are used, they also add nicely ontop of the very bland and boring default light reflections.

How can i use it ?

You can enable Screen Space Reflections by opening 'Preferences' and selecting the 'Display' tab, here you'll navigate into the 'Deferred Rendering' section where you'll find the 'Screen Space Reflections' group, you can turn SSR on or off here.

What can i change?

Screen Space Reflections doesn't offer much options outside of the resolution and brightness both options which can be found right next to the feature toggle itself. There really isn't much to change about Screen Space Reflections anyway, its highly dependent on the user content it is used on.

Caveats

It's not exactly accurate nor realistic and as screen space limited feature also fails on the screen edges and cannot include objects or landscape outside of your screen. It is also a semi-expensive GPU shader feature and GPU's similar to a GTX 600 series will start to slow down if the resolution is set higher than ~13.

Screen Space Reflections do not scale with resolution, this means that if you take snapshots at higher or lower resolution than your current window you might have to reconfigure Screen Space Reflections for these resolutions, Screen Space Reflections shares this weird behavior with 'Light Softening', 'Depth of Field' , 'Screen Space Ambient Occlusion' and 'Volumetric Lighting'. Keep this in mind.