| 摘要 |
<p>The method includes inputting a plurality of points comprising an image to be displayed, wherein each of the points is described by X, Y, Z and W world coordinates. The points are stored in the memory coupled to the CPU. The CPU executes a viewing algorithm which transforms the world coordinates for each point into view reference coordinates. The view reference coordinates have an origin at the viewpoint of the user, with the Z axis pointed outward in the direction of the display screen. Each of the points of the image are described by clipping bits X Right, X Left, Y, Top, Y Bottom, Z Back, and Z Front. The view reference coordinate system of the present invention permits the user to selectively enable/disable clipping quadrants in X, Y, Z and W space. The method determines the value of the clipping bits for all of the points (vertices) comprising the image. Using predefined combinational logic, the method evaluates the clipping bits and determines if the image is visible, hidden, or if it intersects at least one clipping plane. The method provides an efficient means for determining if a three dimensional image is to be displayed on a computer display system. …<IMAGE>… </p> |
