1. A computer-implemented method for generating a multiscale three-dimensional reference grid positioned in a graphics workspace, the method comprising: determining a closest point disposed on a plane of the three-dimensional reference grid and viewable by a camera; computing a scale for the three-dimensional reference grid based on the coordinates of the closest point; rendering the graphics workspace and the three-dimensional reference grid as viewed from the camera to produce a display image, wherein the spacing of grid lines in the three-dimensional reference grid is based on the computed scale; and storing the display image in a memory or displaying the display image on a display device.