This Unity sample project demonstrates how to blend Unity renders in OBS by using inter-app frame interchange protocols such as Spout, Syphon, or NDI. It relies on URP's alpha-channel output, so chroma keying (green background) is unnecessary.

It uses the following packages:

• KlakSpout (Windows)
• KlakSyphon (Mac)
• KlakNDI (Windows/Mac)

Although both are included for demonstration, choose whichever suits your project.

• Set a camera render target to a Render Texture that supports alpha (for example, R8G8B8A8_SRGB). A Game View sender won't work because it lacks alpha data.
• Enable the "Alpha Processing" switch in the Universal Render Pipeline asset if you rely on post-processing.
• In Spout/Syphon/NDI sender components, use the "Texture" capture method with that render texture and enable "Keep Alpha".

• Bloom is discouraged because it has no influence on the alpha channel, so results are rarely desirable.
• If you're unsure about tonemapping, disable it, especially for non-photorealistic rendering.
• Use the AlphaBypass hack only when alpha interference in post-processing becomes a problem.