Spout2 Background - ebikatsudon/VTubeStudio GitHub Wiki

VTube Studio supports Spout2 backgrounds (Windows only).

When you select that special background, it shows you a list of available Spout2 sources (excluding ones created by VTube Studio). Selecting a source will render the video sent via Spout2 as background in VTube Studio.

Using this, you could for example use OBS (you can start OBS multiple times) to record some window and them stream it into VTS using the OBS Spout2 Output plugin.

⚠️ ⚠️ ⚠️ This will show whatever is shown in the Spout2 stream directly in VTube Studio. Like an OBS "screen capture", this can be very dangerous and potentially show private information. NEVER EVER HAVE YOUR WEBCAM ADDED ANYWHERE IN OBS FOR ANY REASON. Be careful with this!! ⚠️ ⚠️ ⚠️

Also, be careful about the resolution of the Spout2 source you select. Having a very high resolution may cause lag, so it's recommended to keep streams at 1920x1080 at most.