WebCamTexture.deviceName
var deviceName: string;
Description

Set this to specify the name of the device to use.

This only has an effect when set while the camera is not running.
	// Sets the device of the WebCamTexture to the first one available and starts playing it
	function Start () {
		var devices : WebCamDevice[] = WebCamTexture.devices;
		var webcamTexture : WebCamTexture = WebCamTexture();
		if(devices.length > 0){
            webcamTexture.deviceName = devices[0].name;
			webcamTexture.Play();
		}
	}