PEAK Local Multiplayer - Nucleus Co-op Handler

This is a handler I made for nucleus co-op. It enables split-screen local multiplayer for PEAK using Nucleus Co-op. Play with multiple controllers (e.g. Xbox controllers, PS5 via DS4Windows) and/or keyboard/mouse on a single PC. I hope it helps you play with your loved ones and have a good time. Peak is really special on couch co-op!

Installation

1. Install Nucleus Co-op to somewhere e.g. C:\NucleusCoop.
2. Copy the files inside the 'handlers' folder inside this mod package, and place the contents into NucleasCoop's handlers folder e.g. C:\NucleusCoop\handlers.
3. Open NucleusCoop.exe, click the search icon, and select peak.exe (e.g., C:\Program Files (x86)\Steam\steamapps\common\PEAK\peak.exe).
4. For PS5 controllers, install DS4Windows and set them to emulate Xbox 360 controllers (Click "Edit" under "Selected Profile" section, go Other tab, Change "Emulated Controller" to "Xbox 360")
5. Press some buttons on the controller and they should show up in nucleus.
6. Press the split screen view to get the split screen configuration you want. Then drag and drop the controllers and/or keyboards onto different segments of the screen.
7. Press the right green arrow at the top right of nucleas and select either dx12 or vulkan and click the play button on the right middle of the app.
8. Host a co-op game in one instance and use the invite kiosk to invite the others, an invite overlay should appear, click on invite all with your main mouse cursor. Disable any external overlays (like msi after burner or the nvidia overlay) if the invite overlay is not showing. If you use keyboards and mice after all the instances have launched, resized and positioned correctly, press the END key once to lock the input for all instances to have their own working cursor and keyboard, you need to left click each mouse to make the emulated cursors appear after locking the input. Press the END key again to unlock the input when you finish playing.

Note if one screen lags, press ctrl+h to balance fps across screens (as it unfocuses all windows) or for more fixes check this: https://www.splitscreen.me/docs/faq/#25--why-are-my-in-game-frames-per-second-lowbetter-in-one-instance-than-in-the-others-when-using-nucleus-co-op

Requirements

• Latest Nucleus Co-op (v2.4.0 or newer)
• PEAK installed via Steam
• Internet connection for server-based multiplayer

Notes

• Disable overlays (e.g., MSI Afterburner, NVIDIA) to avoid issues.
• Press End to lock inputs, Ctrl + H for FPS balancing.
• To get mods working you'll need gale on single instance and hit launch multiple times. There's some discussion about this on quack's discord channel for more info/debugging: https://discord.com/channels/1363179626435707082/1391156523216142458

Credits

• quackandcheese for LocalMultiplayer mod inspiration