All of Nintendo's pre-launch trailers for Zelda: Tears of the Kingdom showed off Link flying through the sky and exploring a new archipelago of sky islands floating over Hyrule. It's safe to say the sky is a pretty important part of the game, so it's only fitting that the developers behind Switch emulator Yuzu fixed the clouds first.
"Fix Tears of the Kingdom flickering clouds and depths geometry," reads the update, logged around 4 pm Pacific time. Zelda wasn't out in the US until 9 pm Pacific, but its global midnight launch meant that with an Australian or Japanese Switch account, the emulator developers could already have their hands on it—without touching the pirated copies of the game floating around for the last two weeks.
"We only begin working on emulating new titles once we can legally acquire and dump them ourselves," says Bunnei, Yuzu's project lead. "Since Nintendo Switch releases are region-based, we become legally able to work on them as soon as the title becomes available somewhere in the world. Most issues with TotK in Yuzu (thus far) have been fixed with minor changes that were quick to debug and easy to resolve. I think the fact that the community was able to solve many of these challenges with mods well ahead of us is evidence to that."
Bunnei is referring to the patches and custom emulator builds that have been distributed on piracy subreddits and Discords ever since Tears of the Kingdom's leak. They've been a real mess for the emulation developers, causing blanket bans on discussing Tears of the Kingdom emulation in the Discord servers of Yuzu and Ryujinx until release. Now that the game is officially out there the general chat channels of both servers are flooded with Zelda talk, and the emulator developers have leapt into action.
Starting early on Thursday, updates for Ryujinx tackled a host of issues for Tears of the Kingdom:
- Fixing a crash related to shader caching
- Fixing an audio channel mapping issue that broke audio
- Fixing a texture artifacting issue
- Fixing some visual glitches on the Vulkan backend
- Fixing an aliasing issue affecting the UI
Yuzu has gone through fewer granular changes so far, but is also running the game very well already. An update early Friday fixed a flickering shadow issue, and more will likely roll into Yuzu's "early access" build throughout the weekend. Here's an example of Tears of the Kingdom running at a consistent 4K, 30 fps in Yuzu:
"Considering the length of time that TotK has been in development, we had expected Nintendo's BotW engine to undergo significant advancements, presenting us with a fresh set of technical challenges," says Bunnei. "Nevertheless, we still hedged a bet that doubling-down on improving BotW ahead of this title's release would be beneficial. Our efforts resulted in an approximate 40% average performance increase, and it appears that this work is primarily responsible for TotK performing exceptionally well in Yuzu from the start."
It's still shy of flawless, of course; some players report crashing and a memory leak that causes Yuzu to gobble up more than a dozen gigabytes of VRAM. According to Bunnei, Tears of the Kingdom is VRAM hungry because it "heavily uses a compressed image format, ASTC, that is expensive to emulate on desktop GPUs." But it shouldn't cause problems for most players, as the emulator is meant to periodically clean up the cached memory.
"I can say that if you're running on our recommended hardware and settings, I don't expect you to have problems. Members of our team have already confirmed that you can play for many hours without hitting issues," Bunnei says.
Overall performance will no doubt increase over time, lowering the bar from the high-end systems currently required to play Tears of the Kingdom without any framerate struggles. In the coming weeks we'll see both emulators charge forward with improvements as player interest peaks.
Since May 1, both Yuzu and Ryujinx have seen a surge in Patreon backers. Yuzu, which offers exclusive early builds of the emulator via Patreon, has increased from $18,000 to more than $28,000 from 2,500 new patrons. Ryujinx's Patreon income has risen to nearly $2,500, from the $1,900-$2,000 range it's been hovering at all year. Ryujinx's Patreon doesn't include early builds of the emulator, but it's currently very close to the $2,500 goal, which will allow project founder gdkchan to work on development full time.
While the emulator developers themselves work on fixing bugs and understanding exactly how Tears of the Kingdom makes use of the Switch hardware, they're not the only ones tinkering with it. Modders are also messing with the game's code and already bringing 60 fps Tears of the Kingdom within reach.