Assisted object placement in a three-dimensional visualization system

Disclosed is a method, implemented in a visualization device, to assist a user in placing 3D objects. In certain embodiments the method includes displaying, on a display area of the visualization device, to a user, various virtual 3D objects overlaid on a real-world view of a 3D physical space. The method can further include a holding function, in which a first object, of the various virtual 3D objects, is displayed on the display area so that it appears to move through the 3D physical space in response to input from the user, which may be merely a change in the user's gaze direction. A second object is then identified as a target object for a snap function, based on the detected gaze of the user, the snap function being an operation that causes the first object to move to a location on a surface of the target object.