How to save a Render Texture to a file?

I'd like to know of a way to save the content of a render texture to a file. I'm not trying to do a simple screenshot, so I can't just use Texture2D.ReadPixels().

The content of the render texture can't be displayed. I'm trying to get high-res screnshots. For this I create a high-res render texture (x times the actual game window size) that I attach to a camera, and perform a camera.Render(), which draws the content of the scene into the render texture. So here I am with a super high quality scene, but I don't know how to save that to a file :|


You can use ReadPixels with a rendertexture; see the docs.