Yes, you can choose the 3D position from where the line of sight is calculated. Each line of sight source is controlled by a unity camera component which you can move and rotate freely in the world. So anything that's visible from that camera's viewpoint will be masked as visible. You can combine any series of image effects to get the result you desire. There are several blur image effects that ship with the pro version of Unity you can use, and I've included a custom desaturate (black and white) effect with the asset. If I find the time, I'll work on creating a new demo.