SYSTEM, METHOD, AND COMPUTER PROGRAM PRODUCT FOR SHADING USING A DYNAMIC OBJECT-SPACE GRID

• US 20160048999A1
• Filed: 03/11/2015
• Published: 02/18/2016
• Est. Priority Date: 08/12/2014
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Patney, Anjul, Enderton, Eric B., Lum, Eric B., Salvi, Marco, Wyman, Christopher Ryan, Zhang, Yubo, He, Yong, Hart, G. Evan Jr., Fatahalian, Kayvon, Uralsky, Yury, Moreton, Henry Packard, Lefohn, Aaron Eliot
• Granted Patent: US 9,754,407 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 17/20 Finite element generation, e.g. wire-frame surface description, tesselation
• CPC Class Codes: G06T 17/205 Re-meshing
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2210/36 Level of detail

Abstract

A system, method, and computer program product are provided fir shading using a dynamic object-space grid. An object defined by triangle primitives in a three-dimensional (3D) space that is specific to the object is received and an object-space shading grid is defined for a first triangle primitive of the triangle primitives based on coordinates of the first triangle primitive in the 3D space. A shader program is executed by a processing pipeline to compute a shaded value at a point on the object-space shading grid for the first triangle primitive.

Claims

1. A method comprising:

receiving an object defined by triangle primitives in a three-dimensional (3D) space that is specific to the Object;

defining an object-space shading grid for a first triangle primitive of the triangle primitives based on coordinates of the first triangle primitive in the 3D space; and

executing, by a processing pipeline, a shader program to compute a shaded value at a point on the object-space shading grid for the first triangle primitive.

2. The method of claim 1, wherein the coordinates comprise coordinates of a first vertex, a second vertex, and a third vertex that define the first triangle primitive.

3. The method of claim 2, wherein the point corresponds to the first vertex.

4. The method of claim 3, further comprising:

executing, by the processing pipeline, the shader program to compute a second shaded value at a second point that corresponds to the second vertex; and

executing, by the processing pipeline, the shader program to compute a third shaded value at a third point that corresponds to the third vertex.

5. The method of claim 4, further comprising computing a shaded sample at a location within the first triangle by interpolating the first, second, and third shaded values.

6. The method of claim 5, wherein the interpolating comprises barycentric interpolation.

7. The method of claim 1, wherein the object-space shading grid comprises an additional level of the first triangle primitive, the additional level comprising four sub-triangles produced by bisecting each edge of the first triangle primitive.

8. The method of claim 1, wherein the object-space shading grid is mipmapped such that each higher resolution mip level defines additional sub-triangles within the first triangle primitive.

9. The method of claim 8, further comprising:

transforming a screen-space pixel into the 3D space that is specific to the object to generate a footprint; and

identifying a first mip level of the mipmapped object-space shading grid that includes a sub-triangle having an area that most closely approximates an area of the footprint.

10. The method of claim 9, further comprising identifying a second mip level of the mipmapped object-space shading grid that includes a sub-triangle having an area that closely approximates the area of the footprint.

11. The method of claim 10, further comprising executing, by a processing pipeline, a shader program to compute a second shaded value at a second point on the object-space shading grid for the sub-triangle.

12. The method of claim 11, wherein the sub-triangle is defined by the point, the second point on the object-space shading grid, and a third point on the object-space shading grid.

13. The method of claim 12, further comprising;

executing, by a processing pipeline, a shader program to compute a third shaded value at the third point for the sub-triangle;

computing a shaded sample at a sample location within the sub-triangle based on the shaded value, the second shaded value, and the third shaded value.

14. The method of claim 1, further comprising:

transforming a screen-space pixel into the 3D space that is specific to the object to generate a footprint defined by at least a first sample location; and

determining that a sub-triangle within the first triangle encloses the first sample location.

15. The method of claim 14, further comprising, executing, by a processing pipeline, a shader program to compute a second shaded value at a second point on the object-space shading grid that corresponds to a first vertex of the sub--triangle.

16. The method of claim 1, wherein the coordinates are barycentric coordinates.

17. A system comprising:

a processing pipeline that is configured to;

receive an object defined by triangle primitives in a three-dimensional (3D) space that is specific to the object;

define an object-space shading grid for a first triangle primitive of the triangle primitives based on coordinates of the first triangle primitive in the 3D space; and

execute a shader program to compute a shaded value at a point on the object--space shading grid for the first triangle primitive.

18. The system of claim 17, wherein the object-space shading grid is mipmapped such that each higher resolution mip level defines additional sub-triangles within the first triangle primitive.

19. The system of clam 17, wherein the coordinates are barycenric coordinates.

20. A computer-readable storage medium storing instructions that, when executed by a processor, causes the processor to perform steps comprising:

receiving an object defined by triangle primitives in a three-dimensional (3D) space that is specific to the object;

defining an object-space shading grid for a first triangle primitive of the triangle primitives based on coordinates of the first triangle primitive in the 3D space; and

executing, by a processing pipeline, a shader program to compute a shaded value at a point on the object-space shading grid for the first triangle primitive.