In this follow-up to my OBS + Unreal NDI workflow video, I show you how to set up a GPI trigger system similar to what big productions use — without needing actual hardware GPIO pins.

Instead, we use HTTP requests and OBS browser sources to trigger Unreal Engine animations or functions remotely, just by switching OBS scenes. This is perfect for VTuber setups, virtual studios, or graphics.

I demonstrate how to build a reusable HTML browser source that sends dynamic commands to Unreal using Remote Control Presets and the Remote Control API. This lets us switch scenes and trigger different animations, lower thirds, or actions — all with zero operator intervention!

I also show how to use URL parameters to make one HTML file handle multiple triggers, giving you flexible control without rewriting code for each use case.