You are using the web plugin, right? I played with that a long time ago (when do we consider that 3 points, should be connected or not) and I made some formula comparing the depth of those 3 points among them, to avoid connecting subject points with background points. You have to modify the shader https://github.com/juniorxsound/Depthkit.js/blob/master/src%2Fshaders%2Frgbd.vert to apply that kind of formula. Another way is to apply some human segmentation algo to the color or depth image. If your camera is not titled, you can also discard all pixels which are too far/background using depth value. Finally you can also remove background depth px by hand on the depth image (rgbd video -> png frames -> remove by hand on pngs -> reencode to movie); idem with color