Method and system for early Z test in title-based three-dimensional rendering

Abstract

A method and system for an early Z test in a tile-based three-dimensional rendering is provided. In the method and system for an early Z test, a portion which is not displayed to a user is removed prior to performing a rasterization process, and thereby performing the 3D rendering efficiently. The method includes segmenting a scene into tiles for performing a rendering with respect to a triangle; selecting a first tile of the tiles, which has a tile Z value less than a minimum Z value of the triangle; and performing the rendering with respect to the triangle in remaining tiles excluding the selected first tile of the tiles.

1 . An early Z test method, the method comprising:
 segmenting a scene into a plurality of tiles for performing a rendering with respect to a triangle;   selecting a first tile of the plurality of tiles, which has a tile Z value less than a minimum Z value of the triangle; and   performing the rendering with respect to the triangle in remaining tiles excluding the selected first tile of the plurality of tiles.   
   
   
       2 . The method of  claim 1 , wherein the minimum Z value is a smallest Z value among Z values of three vertices of the triangle. 
   
   
       3 . The method of  claim 1 , wherein the tile Z value is a smallest value of maximum Z values of triangles which completely include the tiles. 
   
   
       4 . The method of  claim 3 , wherein the maximum Z value is a greatest value of Z values of three vertices of the triangle. 
   
   
       5 . The method of  claim 3 , further comprising:
 selecting a second tile which is completely included in the triangle from the plurality of tiles; and   updating the tile Z value with the maximum Z value of the triangle, if the maximum Z value of the triangle is less than the tile Z value of the selected second tile.   
   
   
       6 . The method of  claim 5 , wherein the selecting of the second tile which is completely included in the triangle comprises:
 identifying a discrimination value of a tile node of each of the plurality of tiles; and   basing the selecting the second tile which is completely included in the triangle on the discrimination value.   
   
   
       7 . The method of  claim 6 , wherein:
 the discrimination value of the tile node comprises a first discrimination value, a second discrimination value, and a third discrimination value, and   the selecting the second tile which is completely included in the triangle based on the discrimination value further comprises determining the first discrimination value, the second discrimination value, and the third discrimination value based on a sign of a half-plane edge function value with respect to each of a first edge, a second edge, and a third edge of the triangle in the tile node of each of the plurality of tiles.   
   
   
       8 . The method of  claim 7 , wherein the selecting the second tile which is completely included in the triangle based on the discrimination value further comprises selecting a tile which has a positive number for the first discrimination value, the second discrimination value, and the third discrimination value, with respect to all the tile node included in the tile of the plurality of tiles, as the tile which is completely included in the triangle. 
   
   
       9 . A computer-readable recording medium storing a program for implementing an early Z test method, the method comprising:
 segmenting a scene into a plurality of tiles for performing a rendering with respect to a triangle;   selecting a tile from the plurality of tiles which has a tile Z value less than a minimum Z value of the triangle; and   performing the rendering with respect to the triangle in remaining tiles excluding the selected tile of the plurality of tiles.   
   
   
       10 . An early Z test system, the system comprising:
 a tile segmentation unit which segments a scene into a plurality of tiles for performing a rendering with respect to a triangle;   a tile selection unit which selects a tile from the plurality of tiles which has a tile Z value less than a minimum Z value of the triangle; and   a rendering unit which performs the rendering with respect to the triangle in remaining tiles excluding the selected tile of the plurality of tiles.   
   
   
       11 . The system of  claim 10 , wherein the minimum Z value is a smallest Z value among Z values of three vertices of the triangle. 
   
   
       12 . The system of  claim 10 , wherein the tile Z value is a smallest value of maximum Z values of triangles which completely include the plurality of tiles. 
   
   
       13 . The system of  claim 10 , further comprising:
 a tile Z value update unit which selects a tile which is completely included in the triangle from the plurality of tiles and updates the tile Z value with the maximum Z value of the triangle, if the maximum Z value of the triangle is less than the tile Z value of the selected tile.