Assassin’s Creed Unity meets gaming’s “great frame rate debate”

It's been an interesting week for people who like to quantify the technical and graphical performance of games. It's also been interesting for Ubisoft, which has been busy walking back statements after inadvertently setting off a debate regarding how hardware power, frame rates, and artistry all factor in to modern game design.

The issue began on Monday, when Assassin's Creed Unity Senior Producer Vincent Pontbriand told Videogamer.com that Assassin's Creed Unity was being locked at a 900p resolution and 30 frames per second on both the PS4 and Xbox One. That's somewhat noteworthy in itself, given the interest in counting pixels and frames as a way of comparing the two systems' power, but it was Pontbriand's stated reasoning that really gave the story legs.

"We decided to lock them at the same specs to avoid all the debates and stuff," Pontbriand told VideoGamer.com.

Of course, with that statement, those "debates and stuff" flared up fiercer than ever. Gamers flooded Twitter under the hashtag #PS4NoParity, angry at the idea that the game's performance on Sony's system was presumably being scaled back to avoid showing up the Xbox One version.

Gaming forums and YouTube talking heads weighed in on the matter with ferocity.

Ubisoft quickly issued a statement assuring fans that it isn't holding back any version of the game for the sake of console parity. "To set the record straight, we did not lower the specs for Assassin's Creed Unity to account for any one system over the other," the statement reads. "At no point did we decide to reduce the ambitions of any SKU. All benefited from the full dedication of all of our available optimization resources to help them reach the level of quality we have today with the core Assassin's Creed Unity experience."

In another statement, published yesterday, Ubisoft stated bluntly that it "does not constrain its games. We would not limit a game’s resolution. And we would never do anything to intentionally diminish anything we've produced or developed."

Pontbriand himself said in that statement that he "simply chose the wrong words when talking about the game's resolution, and for that I'm sorry."

“We could be running at 100 fps if it was just graphics”

Taking Ubisoft at its word, then, how does the company explain the game coming in below the "1080p/60 fps" that's increasingly seen as the gold standard for the latest generation of console games? It's partly an artistic decision and partly about prioritizing things other than pure graphical numbers, the company says.

In his initial interview with VideoGamer.com, Pontbriand noted that running the artificial intelligence for the game's massive crowds eats up a lot of the systems' computing bandwidth. "Technically we're CPU-bound," he said. "The GPUs are really powerful, obviously the graphics look pretty good, but it's the CPU [that] has to process the AI, the number of NPCs we have on-screen, all these systems running in parallel."

"It's not the number of polygons that affect the framerate," he continued. "We could be running at 100 fps if it was just graphics, but because of AI, we're still limited to 30 frames per second."

Rather than simply maximizing the resolution and frame rate numbers, Ubisoft says it wanted to prioritize features that improve the gameplay experience, including those AI crowds and environments scaled precisely to the real world (rather than the three-quarters scale of older games in the series).

"Keep in mind that previous Assassin's Creed games could support around 100 to 150 NPCs [on-screen at once]," Ubisoft said in Thursday's statement. "Assassin's Creed Unity has crowds of thousands of NPCs on-screen, and you can interact with each and every one of them."

In further statements, Ubisoft took aim at the idea that 60 frames per second even made games look much better. "At Ubisoft for a long time we wanted to push 60 fps," Unity World Level Design Director Nicolas Guérin told TechRadar. "I don't think it was a good idea because you don't gain that much from 60 fps and it doesn't look like the real thing. It's a bit like The Hobbit movie; it looked really weird."

Creative Director Alex Amancio added that 30 fps "feels more cinematic" and that scaling the frame rate back "lets us push the limits of everything to the maximum. It's like when people start asking about resolution. Is it the number or the quality of the pixels that you want? If the game looks gorgeous, who cares about the number?"

How many frames do we really need?

Ubisoft's explanations raise questions of just how important it is for game makers to prioritize a high frame rate over other factors in designing their games. (Much as "Resolutiongate" raised questions about the value of extra pixels, as Ars has covered previously).

There are plenty of games where showing as many distinct frames as possible is of utmost importance. During my Dance Dance Revolution phase in college, I remember the moment when I was finally able to transition from the 30 fps versions of the games on the original PlayStation to the 60 fps smoothness of DDR Max on the PS2. In a game so obsessed with precise timing and matching visuals to the music, the additional frames actually had an immediate and important impact on the gameplay experience.

For competitive twitch games like first-person shooters, real-time strategy games, and fighting games, pumping up the frame rate matters to the experience. These are games where high-level players literally measure events based on how many frames they take to display and where being "frame-perfect" with an input can mean the difference between success and failure. For those games and players, locking in a frame rate of at least 60 frames per second without a lot of stuttering up and down is of utmost importance.

For games that don't require such precision, though, the focus on frames per second as a measure of a game's overall graphical quality or a system's hardware power is as myopic as focusing on megapixel count when picking a digital camera. Sure, when frame rates dip much below 24 to 30 frames per second, most people start to see animation as jumpy or disjointed. Above that minimum threshold, though, there's an argument to be made that simply pumping up the frame count doesn't need to be the priority in every game.

Sure, all others things being equal, more frames per second is usually a good thing. But when it comes to graphics in games, all things aren't equal. Pushing out more frames every second requires CPU and GPU time that, as Ubisoft points out, could be put toward other things with a much more direct impact on a game's quality, such as AI and environmental modeling. These kinds of things have at least as much impact on the quality of the game experience as the smoothness of its animation, even if they can't be as easily quantified in a number that can be quickly compared between games and systems.

Even when there's plenty of hardware power to spare, an ultra-smooth frame rate isn't necessarily the right artistic choice for every game. Outside of those frame-dependent twitch games, the frame rate can be seen as an important aesthetic choice for a game designer to consider. Like it or not, audiences have been trained by years of TV and movies to see video at the 24 frames movie standard (or the similar 30 fps TV standard) as "cinematic." Visual media that go past those rates can seem unnaturally smooth, an effect that resembles the uncanny valley in computer modeling. For a historically set game like Assassin's Creed Unity, especially, I can see a lower frame rate actually matching the feeling of the time period better than a pumped-up frame rate that approaches "real world" smoothness.

It might sound like excuse-making or "laziness" for a developer not to push that frame rate number as high as possible, but there are valid design trade-offs and artistic issues that make maximum frame rates only one part of a complex equation.