Yes, you can select a virtual camera, such as OBS, as your camera input on Riverside.
However, these programs and other features that enhance your video feed, like the Portrait mode video effect on a Mac, can use a lot of your computer's processing power –– especially while it also records your local video track at a high resolution.
To ensure the best recording and a local High Quality Track with a smooth frame rate, we recommend reducing the Studio's default quality (recording resolution).