Simulating an arbitrary number of particles

• US 8,970,592 B1
• Filed: 04/19/2011
• Issued: 03/03/2015
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Lucasfilm Limited (The Walt Disney Company)
• Original Assignee: Lucasfilm Limited (The Walt Disney Company)
• Inventors: Petterson, Frank Losasso
• Primary Examiner(s): Chauhan, Ulka
• Assistant Examiner(s): BADER, ROBERT N.
• Application Number:
  US13/089,761
• Time in Patent Office: 1,414 Days
• US Class Current: 345/427
• CPC Class Codes: G06T 13/60 of natural phenomena, e.g. rain, snow, water or plants
• CPC Class Codes: G06T 2210/56 Particle system, point based geometry or rendering

Abstract

A system includes a computing device that includes a memory configured to store instructions. The computing device also includes a processor configured to execute the instructions to perform a method that includes obtaining first data corresponding to a first simulation of matter in a space domain. The method also includes performing, using the first data, a second simulation that produces second data representative of particles in the space domain. The method also includes rasterizing the second data representative of the particles as defined by cells of a grid, wherein each cell has a common depth-to-size ratio, and, rendering an image of the particles from the rasterized second data.

Claims

1. A computer-implemented method comprising:

obtaining first data corresponding to a first simulation of fluid matter in a Cartesian space domain, the first data produced from a globally coupled fluid model;

defining a three-dimensional (3D) grid of cells to represent at least a part of the space domain, wherein the 3D grid of cells forms a frustum-shaped perspective grid;

identifying a first plurality of the cells of the 3D grid of cells that contain components of the fluid matter according to the first data;

subdividing the identified cells into a plurality of subcells;

performing, for each of the plurality of subcells, using the first data, a second simulation of the fluid matter that produces second data representative of physical properties of the fluid matter in the subcells, the second simulation being particle-based;

for each subcell, compressing particle simulation information from the second data to produce at least one value for each of a second plurality of cells of the 3D grid; and

storing the values for each of the second plurality of cells in a retrievable form.

2. The computer-implemented method of claim 1, further comprising rendering an image of the fluid from the stored values.

3. The computer-implemented method of claim 2, in which rendering the image includes ray tracing the cells of the 3D grid.

4. The computer-implemented method of claim 1, in which performing the second particle-based simulation is distributed among multiple computing devices that each comprise at least one processor.

5. The computer-implemented method of claim 1, in which the first data comprises a vector field.

6. The computer-implemented method of claim 1, in which the second plurality of cells is determined by which cells of the 3D grid comprise a minimum number of particles of the second simulation.

7. The computer-implemented method of claim 1 in which the cells of the grid have a common depth-to-size ratio.

8. The computer-implemented method of claim 1, wherein the 3D grid of cells forms a frustrum-shaped 3D perspective grid from the perspective of a virtual camera.

9. The computer-implemented method of claim 8, wherein the at least one value produced for a cell nearer to the virtual camera provides greater detail of particle simulation information than the at least one value produced for a cell farther from the camera.

10. A system comprising:

a computing device comprising;

a memory configured to store instructions; and

a processor configured to execute the instructions to perform a method comprising;

obtaining first data corresponding to a first simulation of fluid matter in a Cartesian space domain, the first data produced from a globally coupled fluid model;

defining a three-dimensional (3D) grid of cells to represent at least a part of the space domain, wherein the 3D grid of cells forms a frustum-shaped perspective grid;

identifying a first plurality of the cells of the 3D grid of cells that contain components of the fluid matter according to the first data;

subdividing the identified cells into a plurality of subcells;

performing, for each of the plurality of subcells, using the first data, a second simulation of the fluid matter that produces second data representative of physical properties of the fluid matter in the subcells, the second simulation being particle-based;

for each subcell, compressing particle simulation information from the second data to produce at least one value for each of a second plurality of cells of the 3D grid; and

storing the values for each of the second plurality of cells in a retrievable form.

11. The system of claim 10, in which the processor is configured to render an image of the fluid from the stored values.

12. The system of claim 11, in which rendering the image includes ray tracing the cells of the 3D grid.

13. The system of claim 10, in which performing the second particle-based simulation is distributed among multiple computing devices that each comprise at least one processor.

14. The system of claim 10, in which the first data comprises a vector field.

15. The system claim 10, in which the second plurality of cells is determined by which cells of the 3D grid comprise a minimum number of particles of the second simulation.

16. The system of claim 10 in which the cells of the grid have a common depth-to-size ratio.

17. The system of claim 10, wherein the 3D grid of cells forms a frustrum-shaped 3D perspective grid from the perspective of a virtual camera.

18. The system of claim 10, wherein the at least one value produced for a cell nearer to the virtual camera provides greater detail of particle simulation information than the at least one value produced for a cell farther from the camera.

19. A computer program product tangibly embodied in a non-transitory information carrier and comprising instructions that when executed by a processor perform a method comprising:

obtaining first data corresponding to a first simulation of fluid matter in a Cartesian space domain, the first data produced from a globally coupled fluid model;

defining a three-dimensional (3D) grid of cells to represent at least a part of the space domain, wherein the 3D grid of cells forms a frustum-shaped perspective grid;

identifying a first plurality of the cells of the 3D grid of cells that contain components of the fluid matter according to the first data;

subdividing the identified cells into a plurality of subcells;

performing, for each of the plurality of subcells, using the first data, a second simulation of the fluid matter that produces second data representative of physical properties of the fluid matter in the subcells, the second simulation being particle-based;

for each subcell, compressing particle simulation information from the second data to produce at least one value for each of a second plurality of cells of the 3D grid; and

storing the values for each of the second plurality of cells in a retrievable form.

20. The computer program product of claim 19, further comprising instructions that when executed by the processor perform a method comprising rendering an image of the fluid from the stored values.

21. The computer program product of claim 20, in which rendering the image includes ray tracing the cells of the 3D grid.

22. The computer program product of claim 19, in which performing the second particle-based simulation is distributed among multiple computing devices that each comprise at least one processor.

23. The computer program product of claim 19, in which the first data comprises a vector field.

24. The computer program product of claim 19, in which the second plurality of cells is determined by which cells of the 3D grid comprise a minimum number of particles of the second simulation.

25. The computer program product of claim 19 in which the cells of the grid have a common depth-to-size ratio.

26. The computer program product of claim 19, wherein the 3D grid of cells forms a frustrum-shaped 3D perspective grid from the perspective of a virtual camera.

27. The computer program product of claim 19, wherein the at least one value produced for a cell nearer to the virtual camera provides greater detail of particle simulation information than the at least one value produced for a cell farther from the camera.