SYSTEM AND METHOD FOR CALCULATING MULTI-RESOLUTION DYNAMIC AMBIENT OCCLUSION

• US 20080218517A1
• Filed: 11/19/2007
• Published: 09/11/2008
• Est. Priority Date: 01/24/2007
• Status: Active Grant

• Current Assignee: Henrik Carl Holmdahl
• Original Assignee: Henrik Carl Holmdahl
• Inventors: Holmdahl, Henrik Carl
• Granted Patent: US 8,390,621 B2
• Time in Patent Office: Days
• US Class Current: 345/426
• CPC Class Codes: G06T 15/506 Illumination models
• CPC Class Codes: G06T 15/80 Shading
• CPC Class Codes: G06T 17/10 Constructive solid geometry [CSG] using solid primitives, e.g. cylinders, cubes
• CPC Class Codes: G06T 2219/2012 Colour editing, changing, or manipulating; Use of colour codes

Abstract

A system and method for generating a three-dimensional image is provided. An embodiment of the present invention includes calculating the ambient occlusion at a vertex in multiple, independent stages. Determining the global AO at the vertex may be performed using a first technique. Determining the local AO at the vertex may be performed using a second technique. The total AO can be found as a function of the local AO and global AO.

Claims

1. A method of determining the total ambient occlusion (AO) at a vertex of an object within a frame comprising the steps of:

receiving a signal to produce an image, the image to contain a first object;

determining the location of a vertex of the first object;

determining a global AO at the vertex of the first object using a first technique;

determining a local AO at the vertex of the first object using a second technique;

determining a total AO at the vertex of the first object as a function of the local AO and global AO; and

,

producing the image, the shading at the vertex of the first object to be dependent on the total AO.

2. The method of claim 1, wherein the image contains other objects formed on triangle-based models comprising a plurality of triangles and approximated by sphere-based models comprising a plurality of spheres.

3. The method of claim 2, wherein the local AO is determined as a function of the geometry of a set of triangles in the triangle-based model.

4. The method of claim 2, wherein the global AO is determined as a function of the geometry of a set of spheres in the sphere-based model.

5. The method of claim 1, further comprising:

determining if a second vertex is a redundant vertex; and

,

upon determining that a second vertex is a redundant vertex, not determining a total AO for the second vertex.

6. The method of claim 2, further comprising:

determining a set of spheres of the plurality of spheres that do not contribute to the AO at the vertex.

7. The method of claim 2, further comprising:

determining a set of triangles of the plurality of triangles that do not contribute to the AO at the vertex.

8. A computer program product tangibly embodied in a machine-readable storage device, the product comprising instructions operable to cause a data processing apparatus to:

receive a signal to produce an image, the image to contain a first object;

determine the location of a vertex of the first object;

determine a global AO at the vertex of the first object using a first technique;

determine a local AO at the vertex of the first object using a second technique;

determine a total AO at the vertex of the first object as a function of the local AO and global AO; and

,

produce the image, the shading at the vertex of the first object to be dependent on the total AO.

9. The computer program product of claim 8, wherein the image contains other objects formed on triangle-based models comprising a plurality of triangles and approximated by sphere-based models comprising a plurality of spheres.

10. The computer program product of claim 9, wherein the local AO is determined as a function of the geometry of a set of triangles in the triangle-based model.

11. The computer program product of claim 9, wherein the global AO is determined as a function of the geometry of a set of spheres in the sphere-based model.

12. The computer program product of claim 8 containing further instructions operable to cause the data processing apparatus to:

determine if a second vertex is a redundant vertex; and

,

upon determining that a second vertex is a redundant vertex, not determining a total AO for the second vertex.

13. The computer program product of claim 8 containing further instructions operable to cause the data processing apparatus to:

determine a set of spheres of the plurality of spheres that do not contribute to the AO at the vertex.

14. The computer program product of claim 8 containing further instructions operable to cause the data processing apparatus to:

determine a set of triangles of the plurality of triangles that do not contribute to the AO at the vertex.

15. The computer program product of claim 8, wherein the data processing apparatus is a video game console.