You can use Lines and Text in WebGL right next to your model for example (keep in mind, you cannot use CSS3D or CSS2DRenderers in this case, since they don’t actually render to canvas, they just use HTML overlays which you can’t translate into an image easily.)
Alternatively, you can also render the frame, put it into a separate <canvas> element, then draw using CanvasAPI .fillText and .lineTo.
Both will give pretty much the same effect - the first option being a bit easier since you’re working in the same 3D scene as your model.