How can I open rear camera in mobile device using webcam.js?

Question

I am using webcam.js by https://github.com/jhuckaby/webcamjs and In mobile devices, the front camera is opening by default. I want to change the default to the rear camera. Is there any way to change the camera device?

Answer 1

 var constraints = {
    video: true,
    facingMode: "environment"
};