Camera.Render()?

I was curious if Camera.Render() is supposed to render to the screen when there is a null target texture. I've got a scene with 3 Cameras, each at a different depth. One for my "background", the main scene one, and a third for the UI.

At first, I left background and UI cameras enabled and let them just render, and called mainSceneCam.Render() in a LateUpdate on a script. I assumed it was actually getting cleared by the background camera and that's why I didn't see it. When I disabled the other two cameras, I just got the "Scene is Missing a FullScreen Camera" scene in game, but my debug logs were getting hit in the OnPreCull, OnRenderImage / etc Functions. I tried just blitting the src to dst in on Render image, but no dice.

The only way I could see it is if Rendered the mainSceneCam to a Texture first.

Is that intended? I was hoping to be able to Render directly to screen. Then I could disable all 3 and call render on them in order - which I tried to no avail.

 

Giving this a bump - with more experimenting, I'm pretty sure Camera.Render() doesn't render to the screen with a null texture, but since it's undocumented I wanted to make sure I'm just not missing something.