Creating a ray differential by accessing a G-buffer

Patent metadata

Field	Value
Publication number	US-10600232-B2
Application number	US-201816022506-A
Country	US
Kind code	B2
Filing date	Jun 28, 2018
Priority date	Jan 26, 2018
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A texture level of detail (LOD) approximation may be performed utilizing ray differentials and a G-buffer. For example, a scene to be rendered is identified, and a G-buffer of the scene is rendered. Additionally, ray tracing is started for the scene, and during the ray tracing, a ray differential is created by accessing the G-buffer. Further, the created ray differential is appended to a current ray, and the created ray differential is traced.

First claim

What is claimed is:

1. A method comprising:
identifying a scene to be rendered;
rendering a G-buffer of the scene;
starting ray tracing for the scene;
during the ray tracing, creating a ray differential for a pixel by accessing the G-buffer for the pixel and one or more additional pixels neighboring the pixel;
appending the created ray differential to a current ray; and
tracing the created ray differential.

2. The method of claim 1 , wherein the G-buffer is a screen-sized buffer generated using a pixel shader.

3. The method of claim 1 , wherein one or more attributes are written to the G-buffer for each pixel in the scene when the G-buffer of the scene is rendered.

4. The method of claim 1 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel to the right and to the left within the G-buffer in order to create the ray differential in a x-direction.

5. The method of claim 1 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel above and/or below within the G-buffer in order to create the ray differential in a y-direction.

6. The method of claim 1 , wherein G-buffer entries for pixels closest to the pixel both horizontally and vertically are accessed in order to create the ray differential in a x-direction and a y-direction.

7. The method of claim 1 , wherein a distance t to a hit point is stored in the G-buffer.

8. The method of claim 1 , wherein accessing the G-buffer for the pixel and one or more additional pixels neighboring the pixel includes accessing entries in the G-buffer for the pixel and one or more additional pixels neighboring the pixel, each entry of the entries storing a normal and a distance to a hit point for a corresponding pixel.

9. A system comprising:
a processor that is configured to:
identify a scene to be rendered;
render a G-buffer of the scene;
start ray tracing for the scene;
during the ray tracing, create a ray differential for a pixel by accessing the G-buffer for the pixel and one or more additional pixels neighboring the pixel;
append the created ray differential to a current ray; and
trace the created ray differential.

10. The system of claim 9 , wherein the G-buffer is a screen-sized buffer generated using a pixel shader.

11. The system of claim 9 , wherein one or more attributes are written to the G-buffer for each pixel in the scene when the G-buffer of the scene is rendered.

12. The system of claim 9 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel to the right and to the left within the G-buffer in order to create the ray differential in a x-direction.

13. The system of claim 9 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel above and/or below within the G-buffer in order to create the ray differential in a y-direction.

14. The system of claim 9 , wherein G-buffer entries for pixels closest to the pixel both horizontally and vertically are accessed in order to create the ray differential in a x-direction and a y-direction.

15. The system of claim 9 , wherein a distance t to a hit point is stored in the G-buffer.

16. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, causes the processor to perform steps comprising:
identifying a scene to be rendered;
rendering a G-buffer of the scene;
starting ray tracing for the scene;
during the ray tracing, creating a ray differential for a pixel by accessing the G-buffer for the pixel and one or more additional pixels neighboring the pixel;
appending the created ray differential to a current ray; and
tracing the created ray differential.

17. The non-transitory computer-readable storage medium of claim 16 , wherein the G-buffer is a screen-sized buffer generated using a pixel shader.

18. The non-transitory computer-readable storage medium of claim 16 , wherein one or more attributes are written to the G-buffer for each pixel in the scene when the G-buffer of the scene is rendered.

19. The non-transitory computer-readable storage medium of claim 16 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel to the right and to the left within the G-buffer in order to create the ray differential in a x-direction.

20. The non-transitory computer-readable storage medium of claim 16 , wherein creating the ray differential by accessing the G-buffer includes accessing entries in the G-buffer for the pixel and the one or more additional pixels that neighbor the pixel above and/or below within the G-buffer in order to create the ray differential in a y-direction.

21. The non-transitory computer-readable storage medium of claim 16 , wherein G-buffer entries for pixels closest to the pixel both horizontally and vertically are accessed in order to create the ray differential in a x-direction and a y-direction.

Assignees

• Nvidia Corp

Inventors

• Akenine-Moller Tomas
• Toth Robert
• Andersson Magnus
• Nilsson Jim Kjell David

Classifications

• G06T15/06 Primary

  Ray-tracing · CPC title

• G06T15/04

  Texture mapping · CPC title

• G06T15/10

  Geometric effects · CPC title

• G06T15/80

  Shading · CPC title

• G06T15/005

  General purpose rendering architectures · CPC title