Mouse / Canvas X, Y to Three.js World X, Y, Z

I've searched around for an example that matches my use case but cannot find one. I'm trying to convert screen mouse co-ordinates into 3D world co-ordinates taking into account the camera. Solutions I've found all do ray intersection to achieve object picking. What I am trying to do is position the center of a Three.js object at the co-ordinates that the mouse is currently "over". My camera is at

[korinchan]

マウス座標を平面に投影

[pirosikick]

マウス→3D座標系