Method and apparatus for self shadowing and self interreflection light capture

1. A method for rendering an object associated with an image with high resolution lighting characteristics in real time during a video presentation, comprising:

generating a texture map associated with the image, the texture map defined by texels,

calculating a value representing a lighting characteristic for each of the texels by sampling a center point of the texel; the calculating including,

determining a direct illumination transfer function through a biased approximator for a point of the object in real time; and

determining a secondary lighting contribution in real time, the secondary lighting contribution identified through a series of multiply and add operations, resulting in coefficients that represent surface reflectance; and

combining the coefficients that represent the surface reflectance with the direct illumination transfer function to render the lighting characteristic;

storing the value;

associating a coordinate space of the texture map with a display screen coordinate space; and

rendering the image on a display screen using the stored value.

2. The method of claim 1 , wherein the method operation of calculating a value representing a lighting characteristic for each of the texels includes,

determining visibility from the center point associated with one of the texels; and

determining a distribution of an incoming light ray.

3. The method of claim 2 , wherein an occlusion function is applied to determine the visibility and ray tracing is applied to determine the distribution of incoming light.

4. The method of claim 1 , wherein the method operation of calculating a value representing a lighting characteristic for each of the texels includes,

defining an image associated with a first resolution; and

applying a basis function to determine the value.

5. The method of claim 4 , wherein the value is represented by multiple coefficients.

6. The method of claim 4 , wherein the image on the display screen is associated with a second resolution, the second resolution being less than the first resolution.

7. The method of claim 4 , wherein the method operation of applying a basis function to determine the value includes, executing a transfer function to yield the value.

8. A method for incorporating lighting characteristics of an image of an object into a texture map for display in real time during a video presentation, comprising:

defining a texture map associated with the image;

determining a lighting characteristic associated with a texel of the texture map by sampling a center point of the texel the determining including,

determining a direct illumination transfer function through a biased approximator for a point of the object in real time; and

determining a secondary lighting contribution in real time, the secondary lighting contribution identified through a series of multiply and add operations, resulting in coefficients that represent surface reflectance;

combining the coefficients that represent the surface reflectance with the direct illumination transfer function to render the lighting characteristic;

associating the texel with the lighting characteristic; and

displaying the image of the object according to the lighting characteristic.

9. The method of claim 8 , wherein the method operation of determining a lighting characteristic associated with a texel of the texture map includes,

identifying a point on the object associated with the image; and

calculating the coefficients through the application of a basis function with the center point.

10. The method of claim 8 , wherein the image on the display screen is associated with a first resolution of a model of the object and the image is associated with a second resolution of the model of the object, wherein the first resolution is less than the second resolution.

11. The method of claim 8 , wherein the lighting characteristic includes both self shadowing and self interreflection components.

12. The method of claim 8 , wherein the method operation of determining a lighting characteristic associated with a texel of the texture map includes,

calculating the lighting characteristic in a manner such that an intensity of the lighting characteristic does not fluctuate when a light source is moved.

13. A computer readable medium having program instructions for incorporating lighting characteristics of an image associated with an object into a texture map for display in real time during a video presentation, comprising:

program instructions for defining a texture map associated with the image;

program instructions for determining a lighting characteristic associated with a texel of the texture map by sampling a center point of the texel the program instructions for determining including,

program instructions for determining a direct illumination transfer function through a biased approximator for a point of the object in real time; and

program instructions for determining a secondary lighting contribution in real time, the secondary lighting contribution identified through a series of multiply and add operations, resulting in coefficients that represent surface reflectance;

program instructions for combining the coefficients that represent the surface reflectance with the direct illumination transfer function to render the lighting characteristic;

program instructions for associating the texel with the lighting characteristic; and

program instructions for displaying the image of the object according to the lighting characteristic.

14. The computer readable medium of claim 13 , wherein the program instructions for determining a lighting characteristic associated with a texel of the texture map includes,

program instructions for identifying a point on the object associated with the image and wherein the program instructions for determining the secondary lighting contribution is based on the application of a spherical basis function with the center point of the texel.

15. The computer readable medium of claim 13 , wherein the lighting characteristic includes both self shadowing and self interreflection components.

16. The computer readable medium of claim 13 , wherein the program instructions for determining a lighting characteristic associated with a texel of the texture map includes,

program instructions for calculating the lighting characteristic in a manner such that an intensity of the lighting characteristic does not fluctuate when a light source is moved.

17. An integrated circuit, comprising:

a memory capable of storing data corresponding to a self shadow and self interreflection lighting characteristics associated with an image;

circuitry for accessing the data;

circuitry for determining an intensity associated with a pixel based upon a product of the data and an illumination value, the illumination value derived without calculating the lighting function at triangle corners, the circuitry for determining the intensity including,

circuitry for determining a direct illumination transfer function through a biased approximator for a point of the object in real time; and

circuitry for determining the self shadow and self interreflection lighting characteristics in real time during a video presentation through a series of multiply and add operations, resulting in the data that represent surface reflectance;

circuitry for combining the coefficients that represent the surface reflectance with the direct illumination transfer function to render the lighting characteristic; and

circuitry for enabling presentation of the intensity of the pixel on the display screen.

18. The integrated circuit of claim 17 , wherein the image is associated with an object of a video game and the illumination value is derived by a transfer function that samples a center point of a texel of the object.

19. The integrated circuit of claim 17 , wherein the integrated circuit is incorporated into a video game console.

20. The integrated circuit of claim 17 , wherein the data is associated with a texel of a texture map stored in memory.

21. The integrated circuit of claim 20 , wherein a lookup table maps the texel to the pixel.