发明名称 |
SMOOTH SHADING OF OBJECTS ON DISPLAY DEVICES |
摘要 |
A method for defining a color gradient across a region in a display space that includes defining a bi-cubic patch enclosing the region. The bi-cubic patch includes four corners having a color associated therewith and four curves connecting pairs of the corners forming a closed loop. The four curves define the color gradient across the bi-cubic patch as a function of the four colors associated with the four corners of the bi-cubic patch. The method includes defining a unit square in parameter space including a mapping function from the unit square to the bi-cubic patch such that the corners of the bi-cubic patch map to the corners of the unit square. The color of every point in the unit square is a bi-cubic interpolation of the four colors associated with the four corners of the bi-cubic patch. The method includes clipping the bi-cubic patch for display of the region. In another aspect, the invention provides a method of accurately rendering color gradients across a bi-cubic patch that includes subdividing the bi-cubic patch into sub-patches until each side of a given sub-patch is a good approximation of a line and checking to determine if for all points inside of a given sub-patch the color associated with each point is sufficiently accurate. If not, the sub-patch is further subdivided until the color associated with each point inside a given sub-patch is sufficiently accurate. The method includes dividing the sub-patches into polygons and rendering the polygons.
|
申请公布号 |
CA2234566(A1) |
申请公布日期 |
1998.10.18 |
申请号 |
CA19982234566 |
申请日期 |
1998.04.08 |
申请人 |
ADOBE SYSTEMS INCORPORATED |
发明人 |
FOLEY, MATTHEW J.;CHEN, PAUL C.;BILODEAU, WILLIAM D.;SCHILLER, STEPHEN N. |
分类号 |
G06T15/04;(IPC1-7):G06F3/14;G06T5/00 |
主分类号 |
G06T15/04 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|