Patent ID: 6628281
Filing Date: 2003-09-30
Classification: G06T

Abstract:
A method for rendering a z polygon formed by an intersection of a screen-aligned plane with a bounding volume, the method comprising the computer-implemented steps of:determining an ordered set of bounding volume edges intersected by the screen-aligned plane; for the ordered set of bounding volume edges, calculating a corresponding ordered set of z polygon vertices, wherein each vertex in the ordered set of z polygon vertices is determined by the intersection of the screen-aligned plane with a corresponding edge from the ordered set of bounding volume edges; and rendering the z polygon by connecting the z polygon vertices of the ordered set of z polygon vertices in an order corresponding to the ordered set of z polygon vertices, wherein: the bounding volume is a parallelepiped with eight vertices and twelve edges; the eight vertices are sorted based on increasing z depth; the parallelepiped has one of a first orientation and a second orientation; each vertex of the parallelepiped is at a distinct z depth in either the first orientation or the second orientation; and a calculation to draw each edge of the z polygon requires only three multiplications, two additions, and one subtraction.