Cemu

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Revision as of 22:53, 2 April 2017 by 197.7.14.106 (talk)
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Cemu-Logo.png
Current version: 2.0
Active: Yes
OS: Windows
Authors: Exzap
Official website: Cemu
Source code: Closed source

Cemu is a closed-source, Windows-only Wii U emulator. Currently, the GamePad, Classic, and Pro controllers are emulated. It also requires a high-end PC to run games at full speed, although there are numerous bugs that can crash games due to unimplemented features.

The latest version of Cemu is restricted at first to project donors for a week.[1] It's then followed by a free release with further improvements. The paid version has a simple DRM in place doing a regular online verification, though some dedicated open-source advocates like on mudlord's blog regularly post early pirated copies of that version with the DRM removed.

Downloads

System requirements

  • OS: Windows 7 (64-bit) or above
  • GPU: OpenGL 4.0 or above, Intel iGPUs are not recommended
  • RAM: 4 GB minimum, 6 GB or more recommended

Playing Games

Physical Dumps

You'll first need to fill in the "keys.txt" file in Cemu's directory. It has a sample line with a bogus key and a comment, which you may as well delete.

Your file must have many lines like this, one for the Wii U Common Key (D7B00402659BA2ABD2CB0DB27FA2B656), and one line for the Game Key of each game. Sharing these keys isn't exactly safe legally, but ROM sites at least share the Game ones. Note that for games using the Loadiine format, you won't need a Game Key at all, but those will need Cemu versions from 1.4.0 onward.

Your ISO must be either uncompressed, compressed using WUD format, or in Loadiine format (only possible for versions 1.4.0 onward) to boot in Cemu. Here's a compatibility list.

Digital Copies

CEMU supports either physical games dumps in WUD, or compressed WUX format, as well as game dumps converted to the Loadiine format. Loadiine games come as multiple directories with game files and a rpx file.


Nintendo's servers are poorly secured due to a huge oversight when designing Wii U/3DS software protection. As such, with tickets proving you bought the game (but which you can get through less legit ways), there are downloader utilities like NUSGrabber, FunKiiU, UWizard, or jnus among others, and decryption tools like UWizard and CDecrypt, to obtain a functional copy.

  • Download an NUS downloader such as WiiU USB Helper.
  • Paste this URL into WiiU USB helper when prompted for the titlekey database. - https://wiiu.titlekeys.com/
  • Select the game you want to download, click get it and then download games.
  • This will download the files for the game you chose (the same as the .tik's title). May I suggest that you choose your own region where possible, so the download is quicker (from your regional servers).
  • Now we need to convert the game into Loadiine format so that you can load it in Cemu.
  • Simply right click your newly downloaded game, then click Unpack/Convert to Loadiine (Pack/Unpack - Loadiine/CIA).
  • Load the .rpx file from [Your gamelocation]/code/[yourgame].rpx with cemu.

Updates and DLC

Prior to 1.7.3, only updates were supported though pasting update files on the main game's folders (keeping in mind the main game is in Loadiine format) and overwriting any files. DLC wouldn't work at all through this method, though with some specific games there were workarounds and some could play DLC tracks in Mario Kart 8 through swapping of specific files. From 1.7.3 onwards, proper support for DLC and updates was included in CEMU.

Use the same process as above to download updates. Once decrypted, simply copy and paste these over the original game's files.

To install updates on Cemu (1.7.3+):

  • Play the game at least once
  • Open "log.txt" and find "TitleId of launched game" followed by a 16-digit number. Copy down that 16-digit number.
  • Go to "CEMUFOLDER/mlc01/usr/title" and create a folder with the first 8 digits of that 16-digit code
  • Inside of that folder, create a folder named with the last 8 digits.
  • Put in the files of the update into the folder
  • To apply DLC create a folder inside of the folder with your update and create a folder named "aoc" and put the DLC files into there and simply run the game.

To add DLC to games:

  • Run the game as normal, at least once.
  • Check Cemu's log.txt file and look for a line that says "Mounting local storage (AOC): .\mlc01\usr\title\NUMBERS\NUMBERS\aoc\"
  • Add (create) folders with the same name as the above (substituting the "NUMBERS" bit with the actual numbers) in your cemu\mlc01\etc. file
  • Add any updates (must be added first) and DLC you want to this folder (code, content and meta folders live inside the aoc folder)

Controls

As of 1.7.3d, the Wii U GamePad and the Wii U Classic Controller are emulated, but the Wiimote still isn't emulated yet. You can set up to 8 GamePads in the menu if you want.

Emulated Wii U GamePad features are as follow:

  • Touch Controls: Mouse left click.
  • Tilting and Gyro Controls: Holding the mouse right-click and dragging.
  • Switch Screens between TV and GamePad: "TAB" key, "Ctrl+TAB" to keep focus. TV by default.
  • Microphone: Spoofed, a configurable key simulates blowing on the mic.

A menu allows for loading NFC tags from Amiibos. (More details would be appreciated)

As of now, no online features or 3DS/Wii U connectivity features are possible.

Improving Performance

Shadercaches

Normally, when playing a game in Cemu, a shader cache will be generated as you play. This will cause a lot of stutter and slow the game down the first time you play that level/area/game. Luckily, Cemu allows you to transfer your shader cache, allowing you to download one from a friend (or just someone else on the internet). Reddit seems to be a good place to get these shadercaches. Simply go here and search for the game you want a cache for.

  • Note that it is very difficult to generate a 100% complete shadercache for large games and therefore this will not definitely completely eliminate stuttering.

Transferable shader caches may cause slowdowns in some games, on some graphics cards (observed in Geforce 970s). If this is the case, delete both your transferable and precompiled caches as well as the .bin and /toc file in your NVIDIA GLCache found in C:\Users\(You)\AppData\Roaming\NVIDIA\GLCache\(hexstring)\(hexstring). In this case, you will have to generate your own shaders.

  • This may get fixed after 1.7.0, who knows?

Changing your NVidia control panel settings to look like this might help with shadercache slowdown issues:

Shadercachestuff.png

Native H264 Decoder

Lots of Wii U games use high resolution MP4 videos and render them using codecs intended for the Wii U, which can get slow to emulate, and cause display bugs on CEMU. CEMUhook is a hook utility used in conjunction with CEMU from versions 1.7.3 onward to render these cutscenes with a much faster video codec native to Windows. It's not officially supported though.

Getting more performance

Some users have reported that disabling hyperthreading improves performance in Cemu. On Windows with hyperthreaded cores, turn off processor affinity for imaginary cores. This will be every other core in your processor affinity. To do this, go to the cemu.exe process in task manager, right click, set affinity and then turn off every other core:

Processor affinity.png

References

External links