Yes,

You can connect your PTZOptics camera to the network and pull in a HD video feed into vMix for a video source. First you want to get your camera's IP address and use that in your vMix input. 

Below is a video demonstrating just how easy it is to do so: 


As you can see above we have selected "Stream" for our input and typed in our the URL as "rtsp://192.168.1.88/1" which is Tom's PTZOptics camera he has selected. Now once you click "OK" the camera feed will be available as a input.