Abstract: A method for determining illumination of surface points of an object in a scene from lighting sources includes determining a first thickness map for a first lighting source for the scene, wherein the first thickness map includes a first plurality of thickness values of the object with respect to distance from the first lighting source, determining a surface point on the object, determining a first plurality of thickness values associated with the surface point on the object in response to the first thickness map, determining a first filtered thickness value associated with the surface point on the object in response to the first plurality of thickness values, and determining an illumination contribution from the first lighting source at the surface point in response to the first filtered thickness value.

Abstract: A method and apparatus for rendering shadows. A pre-rendering process implements a two dimensional array or map of depth-based functions, such as a visibility function in z. During rendering of an object scene, these functions are accessed via lookup operations to efficiently determine the function value for a sample point at a given depth. The use of visibility functions allows for partial light attenuation effects. Each visibility function is computed by filtering multiple transmittance functions obtained by casting sample rays from a light source onto an object scene. The visibility function is implemented as a sequence of vertices. Colored shadows are modeled by vertices comprising a depth value and separate visibility function values for red, green, and blue light at a given depth value. Compression is achieved by minimizing the number of vertices needed to represent a visibility function within a desired error tolerance.

Abstract: A method for determining illumination of surface points of an object in a scene from lighting sources includes determining a first thickness map for a first lighting source for the scene, wherein the first thickness map includes a first plurality of thickness values of the object with respect to distance from the first lighting source, determining a surface point on the object, determining a first plurality of thickness values associated with the surface point on the object in response to the first thickness map, determining a first filtered thickness value associated with the surface point on the object in response to the first plurality of thickness values, and determining an illumination contribution from the first lighting source at the surface point in response to the first filtered thickness value.