Patent ID: 7184042

Claim:
A computer program product for use in connection with a computer to provide a computer graphics system for generating a pixel value for a pixel in an image, the pixel value being representative of a point in a scene as recorded on an image plane of a simulated camera, computer graphics system being configured to generate the pixel value for an image using a selected ray-tracing methodology, the selected ray-tracing methodology making use of a ray tree, the ray tree having a ray shot from the pixel into a scene along a selected direction, at least some of the rays recursively splitting into a selected number of additional rays when the respective ray encounters a surface in the scene, each of the split rays being directed along a selected direction, though a selected number of tree levels, the computer program product comprising a computer-readable medium having encoded thereon: A. computer-readable instructions comprising a low-discrepancy sequence generation module configured to enable the computer to generate elements of at least one low-discrepancy sequence; B. computer-readable instructions comprising an intersection indication generation module configured to enable the computer to determine, for one of said rays in the ray tree, whether the one of the rays encounters a surface of an object in the scene; C. computer-readable instructions comprising a ray generation module configured to enable the computer to, when the intersection indication generator makes a positive determination in connection with the one of the rays, generate a selected number “M” of said additional rays each along a splitting direction determined by a respective direction value determined in accordance with ( y i , j ) j = 0 M - 1 = ( Φ b d ⁡ ( i ) ⊕ j M , … ⁢ , Φ b d + Δ ⁢ ⁢ d - 1 ⁡ ( i ) ⊕ Φ b d + Δ ⁢ ⁢ d - 2 ⁡ ( j ) ) , ⁢ where ⁢ ⁢ { Φ b d ⁡ ( i ) , … ⁢ , Φ b d + Δ ⁢ ⁢ d - 1 ⁡ ( i ) } ⁢ ⁢ and ⁢ ⁢ { j M , … ⁢ , Φ b d + Δ ⁢ ⁢ d - 2 ⁡ ( j ) } are low-discrepancy sequences, for selected bases b and dimensions Δd, generated by the low-discrepancy sequence generator, where y i,j refers to a sample point, Φ b is an offset, and where ⊕ represents addition modulo “one” and “i” and “j” are selected integers identifying respective ray instances; and D. computer-readable instructions comprising a function evaluation module configured to enable the computer to generate at least one value representing an evaluation of a selected function using the rays associated with the ray tree, the value generated by the function evaluator corresponding to the pixel value.