Displaying 2D patches with foldover

A method for rendering a two dimensional (2D) mesh associated with an object to achieve a smooth shading across the object, the 2D mesh including a plurality of patches defining a complex gradient including at least one foldover edge, the method comprising:

• creating a list of patches;
• sorting the list to achieve a predefined ordering of patches;
• processing the patches in the list in order including subdividing the patches until each patch or subpatch includes no more than one foldover edge;
• grouping the patches and subpatches into regions divided by a foldover edge;
• defining an ordering for displaying the regions;
• and
• rendering the regions in display order.

A computer program, tangibly stored on a computer-readable medium, for rendering a two dimensional (2D) patch associated with an object to achieve a smooth shading across the object where the 2D patch defines a complex gradient including at least one foldover edge, the computer program comprising instructions for causing a computer to:

• subdivide the patch until each subpatch includes no more than one foldover edge;
• group the subpatches into regions divided by a foldover edge;
• define a ordering for displaying the regions;
• and
• render the regions in order.

A computer program, tangibly stored on a computer-readable medium, for rendering a two dimensional (2D) mesh associated with an object to achieve a smooth shading across the object where the 2D mesh includes a plurality of patches 2D defining a complex gradient including at least one foldover edge, the computer program comprising instructions for causing a computer to:

• create a list of patches;
• sort the list to achieve a predefined ordering of patches;
• process the patches in the list in order including subdividing the patches until each patch or subpatch includes no more than one foldover edge;
• group the patches and subpatches into regions divided by a foldover edge;
• define an ordering for displaying the regions;
• and
• render the regions in display order.

An apparatus for rendering a two dimensional (2D) mesh associated with an object to achieve a smooth shading across the object where the 2D mesh includes a plurality of patches 2D defining a complex gradient including at least one foldover edge, the apparatus comprising:

• means for creating a list of patches;
• means for sorting the list to achieve a predefined ordering of patches;
• means for processing the patches in the list in order including means for subdividing the patches until each patch or subpatch includes no more than one foldover edge;
• means for grouping the patches and subpatches into regions divided by a foldover edge;
• means for defining an ordering for displaying the regions;
• and
• means for rendering the regions in display order.