Processing Reality
Faking physical cameras with post-processing.
Post-processing is the catch-all term for the series of effects applied to the frame of a videogame to make it appear in the intended manner. While these effects can encompass everything from anti-aliasing to ambient occlusion, they are frequently used to replicate the viewpoint of another medium entirely: Cinema. The visual cues typically associated with physical cameras are becoming more commonplace in games. This is primarily due to advances in rendering technology and techniques, because the nuances of a physical camera are much more complex to replicate than they might initially seem. The differences start with an essential discrepancy in how the cameras in our games even work. “Imitating realworld cameras is hard,” says freelance engine programmer Amandine Coget. “Really, really hard, because they have lenses, and the typical renderer uses the math of a pinhole camera (perfect focus everywhere). So depth of field, notably, has to be faked. Depending on the specific effect, the required fidelity level and the performance constraints, it can be anything from a few days for a basic color correction pipeline to years of bleeding-edge research for the perfect bokeh depth of field.” Coget has conducted research for DICE and other studios, where she observed that even developers of cutting-edge technology still rely on analogue methods to create effects like the title screen glitch for Battlefield 4. Apparently, this animation was filmed on a CRT television while the team messed with the power button. “[It’s] still the easiest way to make it look real!” says Coget.
If games aren’t bound to reality, why put so much effort into replicating visual imperfections? “Many games chase the physical camera effects in a bid to appear cinematic,” says Stephen Alexander, lead artist on games including BioShock, The Magic Circle, and upcoming emergent co-op horror game The Blackout Club. “I think, on some level, the presence of these visual elements subconsciously provides a comfortable point of reference that you associate with a familiar way of experiencing visual entertainment.”
achieving photorealism
Industry veteran Trent Polack notes that we often ignore the complexity of physical camera lenses too. He is working on a rendering enhancement feature set for Unreal Engine 4 that aims to be a “physically-accurate camera solution”. One part of the process was finding and deciphering the patents filed for lenses made by companies like Nikon. He adds: “Then there’s the entire process of taking that sample data and using it as a basis for an implementation of a physically-accurate camera that can run in real-time while still enhancing the overall game experience.”
This pursuit of realism can affect the design of a game as much as its visuals. Luca Redwood, developer of games 10000000 and You Must Build a Boat is using the cues of a camera to have a tangible effect on the way players interact with his latest game, a narrative puzzle anthology named Photographs. “I use vignetting to darken and blur the corners of the frame and chromatic aberration to separate the color channels towards the edge of the field of view. Either biologically or through conditioning we already know not to pay attention to these out of focus areas, and any time you can use a shortcut like that in design, it’s well worth doing. It also helps convey a sense of intimacy by restricting the focus to that specific spot. But conversely, the more of these artefacts we introduce we also begin to feel more distant—it naturally makes sense that if you are up close to something you can see it well, and if you are far away not so well, so that intimacy then becomes almost voyeuristic. You can see these characters, you can feel a connection with these characters, but you are also kind of separated,” observes Redwood. “I did this for Photographs because the stories they are telling are tragedies, and that’s exactly what we are trying to achieve—you feel like you are in there with the characters and care about them but at the same time you are removed from it, watching helplessly as things turn bad for them.”
When I started doing research for this piece, I saw post-processing effects as frivolous. Now, having spoken to artists and programmers and engineers across the industry, I see their value. They’re another essential tool in a developer’s toolkit, using the perception of reality depicted by a camera lens to tap into what we as players feel to be real—whether or not it’s true.
“Many games chase the physical camera effects in a bid to appear cinematic”