| 摘要 |
<p>In a figure-processing apparatus which projects and displays a three-dimensional figure except concealed portions on a screen based upon three-dimensional figure data, a window is set about a designated point on the screen, the three-dimensional figure data are clipped to correspond to the window in order to pick up a figure and data for discrimination contained in a view volume corresponding to the window, the data for discrimination thus picked up are stored in a pick buffer and a depth value of a straight line generated in response to the plane of the picked up figure is compared with a depth value that has been set to a depth buffer. When they are in agreement, the data for discriminating the figure to which the straight line belongs are read out of the pick buffer, and the figure data corresponding to the data for discriminating thus read are read out, in order to pick up a figure corresponding to the designated point. In the system of the invention, the figure concealed by another figure is not picked up, so that the figure can be continuously processed without the need of waiting for the completion of the processing of the preceding figure, and the processing time can be shortened.</p> |
