This series of blog posts is intended to delve deep into the development process, starting from scratch and leading to the next release of the mod. If you want to see what it’s like to mod BotW, how to get started, and how to master all the techniques that made a mod like this possible, you’ve come to the right place.
In October 2018, I released a mod for The Legend of Zelda: Breath of the Wild that replaces Link with another one of the five champions: Mipha. This latest update was for the Switch, but a Wii U version exists as well.
The mod features a full replacement of Link’s default armor set (plus a jewelry set, at least on Wii U for now). Notable features include the Lightscale Trident being made unbreakable (except when thrown), the paraglider redesign, the ability to swim much faster and without stamina usage, climb waterfalls and spin attack without the Zora Armor, and even the ability to enter Gerudo Town without a specific outfit.
These changes would be impossible without the Zelda BotW modding community, particularly KillzXGaming who fully reverse engineered the BFRES model format for Wii U and Switch! His program Switch Toolbox is an invaluable part of the development process.
Community member Peregrine also kindly contributed additional changes to go along with the mod, such as Mipha’s Grace Events (text edits and event flow modifications). Pronouns, references to Link being a Hylian, and even Zora reactions to Mipha’s return are all among the changes.
The Future of the Mod
Peregrine is still working on events, focusing on the Wii U version for now. My current goal is to update both the Wii U and Switch versions of the base mod to be identical, with a few extra features to make it more interesting, immersive and accurate. For instance:
Weakness to Electricity
The Zora people sought out a Hylian in BotW in order to deactivate Vah Ruta using Shock Arrows. As most players are aware, this is due to their innate weakness to electricity. Integrating that with the Mipha mod by increasing Link’s damage from electric attacks (to the point that it’s instantly lethal) is coming in the next update.
Original Model Proportions Restoration
In the original release of the Mipha mod, Link’s skeleton is unmodified– the Mipha model was instead stretched to match Link’s proportions in order to use his animations as the player model. While I don’t think it looks too weird, several users have noted the long legs and masculine shoulders. Future installments will use Mipha’s original proportions by matching the bone positions to Mipha’s original NPC model, so that it can be imported directly with minimal changes to the original skinning.
This method isn’t without its own challenges, which we’ll discuss in the next blog post about models.
New Animation Set
It’s possible to reuse animations from other NPCs throughout the world of BotW on Link’s model by editing his actor properties. We’ll get into that more later, but the next addition to the mod will include a more feminine walk cycle.
No Slipping in the Rain
Perhaps a minor change, but one that I think fits well with the amphibious nature of the Zoras, while also addressing a very common player complaint: climbing during rainstorms. I don’t think anybody who’s replaying the game with this mod will miss being unable to climb. No more stamina loss from slipping, and for that matter no more slipping either! Expect that in the next update.
Getting Started Modding BotW
Since the next release of this mod will be on both Wii U and BotW, I’ll have to differentiate the steps between each version of the game. Fortunately, aside from emulation (and the endianness of file formats), it’s mostly identical. Switch Toolbox also automatically handles endianness differences, so the real difference is just how you run the game.
Downloading the latest Cemu allows us to run Wii U games that have been downloaded and decrypted. I can’t help much with that part for obvious legal reasons, but you can look up plenty of resources on how to obtain a dump or dump your own game.
Cemuhook is an optional modification for Cemu that can potentially increase performance by adding/replacing a couple dll files. I can recommend using it, especially on a mid-to-high-end machine.
Shader Caches for BotW can help improve performance while playing, but increase the load time each time you start the game. That said, it’s not a bad idea to start from scratch and play within a small area, bearing with the load times as it compiles during gameplay for the first time. You’ll be restarting the game to test changes frequently.
BCML is a mod manager for Cemu specifically made to merge BotW mods. It uses the Graphics Pack integration of Cemu to load mods within the emulator. Best of all, it can automatically manage the RSTB (Resource Table) of the game– which is the primary cause of crashes from replacing files with bigger ones.
While Yuzu (a Switch emulator) is in active development, you need to dump a number of things from a vulnerable Switch console in order to run it. That said, you may as well use the Switch itself to test mods using Atmosphere’s LayeredFS feature.
First, download AtlaxNX’s latest release of Kosmos. This has everything you need to drop on your SD card in order to use Atmosphere CFW. To use CFW on a compatible Switch, insert the SD card, enter RCM mode (I recommend using a specially made jig), and use TegraRCMSmash to launch the payload (the .bin file that comes with Kosmos).
On your SD card, changed files can be dropped in \atmosphere\titles\01007EF00011E000\romfs, mimicking the original file structure. They will automatically be loaded when the game runs normally. For instance, a modified TitleBG.pack would go in …\romfs\Pack\TitleBG.pack.
And… That’s it! If you need more details, the BotW Modding Community has a wonderful Discord server, as well as several other tutorials. The rest of the tools you need for specific things (like model editing) will be outlined in later posts.