Lighting and shadowing methods and arrangements for use in computer graphic simulations

A graphics device configured to render shadows in a simulated multi-dimensional scene, the arrangement comprising:

• an output to a display screen configured to display image data;
• a memory for storing data including observer data associated with a simulated multi-dimensional scene, and lighting data associated with a plurality of simulated light sources arranged to illuminate said scene, said lighting data including light image data;
• a frame buffer including a first storage area for light accumulation data and a second storage area for resulting image data;
• and
• at least one processor coupled to said memory and said frame buffer and operatively configured to, for each of said plurality of light sources, compare at least a portion of said observer data with at least a portion of said lighting data to determine if a modeled point within said scene is illuminated by said light source and storing at least a portion of said light image data associated with said point and said light source in the first storage area of the frame buffer, then combining at least a portion of said light image data with said observer data, and storing resulting image data in the second storage area of said frame buffer, and outputting at least a portion of said image data in said second storage area of said frame buffer to said display screen via said output.

A shadow rendering method for use in a graphics device, the method comprising the steps of:

• providing observer data of a simulated multi-dimensional scene;
• providing lighting data associated with at least one simulated light source arranged to illuminate said scene;
• for the at least one light source, comparing an alpha value associated with a portion of said observer depth data with an alpha value associated with a portion of said light source data to determine corresponding modeled points illuminated by said light source and comparing at least a portion of said observer data with at least a portion of said lighting data to determine if a modeled point within said scene is illuminated by said light source and storing at least a portion of said light image data associated with said point and said light source in a portion of a frame buffer;
• combining at least a portion of said portion of said frame buffer with said observer data;
• and
• outputting a resulting image data to a computer screen.

An arrangement configured to render shadows in a simulated multi-dimensional scene, the arrangement comprising:

• an output to a display screen configured to display image data;
• a memory for storing data including observer data associated with a simulated multi-dimensional scene, and lighting data associated with a plurality of simulated light sources arranged to illuminate said scene, said lighting data including light image data;
• a frame buffer including a first storage area for light accumulation data and a second storage area for resulting image data;
• and
• at least one processor coupled to said memory and said frame buffer and operatively configured to, for each of said plurality of light sources, compare an alpha value associated with a portion of said observer data with an alpha value associated with a portion of said light source data to determine corresponding modeled points illuminated by said light source, compare at least a portion of said observer data with at least a portion of said lighting data to determine if a modeled point within said scene is illuminated by said light source and storing at least a portion of said light image data associated with said point and said light source in the first storage area of the frame buffer, then combining at least a portion of said light image data with said observer data, and storing resulting image data in the second storage area of said frame buffer, and outputting at least a portion of said image data in said second storage area of said frame buffer to said display screen via said output.