System and method for efficiently simulating and imaging realistic water surface and other effects

• US 20030090484A1
• Filed: 11/13/2002
• Published: 05/15/2003
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Nintendo Company Limited
• Original Assignee: Nintendo Company Limited
• Inventors: Fam, Sun, Comair, Claude, Ghali, Prasanna
• Granted Patent: US 7,539,606 B2
• Time in Patent Office: Days
• US Class Current: 345/420
• CPC Class Codes: A63F 2300/6615 using models with different levels of detail [LOD]
• CPC Class Codes: A63F 2300/663 for simulating liquid objects, e.g. water, gas, fog, snow, clouds
• CPC Class Codes: G06T 13/60 of natural phenomena, e.g. rain, snow, water or plants
• CPC Class Codes: G06T 15/04 Texture mapping
• CPC Class Codes: G06T 17/20 Finite element generation, e.g. wire-frame surface description, tesselation

Abstract

Water surface and other effects are efficiently simulated to provide real time or near real time imaging on low-capacity computer graphics computation platforms. Water and other surfaces are modeled using multiple independent layers can be dynamically adjusted in response to real time events. The number of layers used in a given area can be adjusted to reduce computational loading as needed. Different algorithms can be employed on different layers to give different effects. The multiple layer modeling is preferably converted to polygons using an adaptive polygon mesh generator based on camera location and direction in the 3D world to provide automatic level of detailing and generating a minimal number of polygons. The visual effects of water droplets and other coatings on see-through surfaces can be modeled and provided using indirect texturing.

Claims

1. A method of producing computer-generated fluid effects comprising:

modeling a fluid surface using a plurality of surface modeling layers;

dynamically changing the number of said plurality of layers to make efficient use of processing resources; and

generating an image of a surface in response to said dynamically changed number of modeling layers.

2. The method of claim 1 wherein said image generating step includes generating a polygon mesh based on camera location.

3. The method of claim 1 wherein said image generating step includes generating a polygon mesh based on camera direction.

4. The method of claim 1 wherein said image generating step includes generating a polygon mesh based on camera location and direction.

5. The method of claim 1 wherein said plurality of layers include a natural wave layer.

6. The method of claim 1 wherein said plurality of layers include a wave generator layer.

7. The method of claim 1 wherein said plurality of layers include a wake layer.

8. The method of claim 1 wherein said plurality of layers include a radial wave layer.

9. The method of claim 1 wherein said plurality of layers include a wind wave layer.

10. The method of claim 1 wherein said plurality of layers include at least one wave layer of a first type and a plurality of wave layers of a second type different from said first type.

11. The method of claim 1 wherein at least one of said plurality of layers is modeled based on a wave starting location, a wave ending location, a wave width, a wave height, a wave period and a wave length.

12. The method of claim 1 further including using indirect texture mapping to provide water droplet distortion effects.

13. A method of imaging fluid effects using a computer comprising:

providing a digital model of a fluid surface;

specifying a camera location and direction at least in part in response to user inputs;

dynamically generating a polygon mesh from said model based at least in part on said specified camera location and direction; and

rendering polygons in said mesh to produce images on a display.

14. The method of claim 13 wherein said polygon mesh generating step determines a position by interpolating between a point of intersection between a camera direction vector and the fluid surface, and a point of intersection of a lower camera frustum vector with said fluid surface, and using said interpolated location to generate polygons.

15. The method as in claim 14 further including generating smaller polygons near said interpolated location and generating larger polygons further away from said interpolated location.

16. The method as in claim 13 wherein said model comprises multiple independent virtual layers.

17. A method of generating images of effects produced by a coating at least partially covering a viewing surface comprising:

creating an indirect texture map modeling distortion due to a coating on the viewing surface;

using said indirect texture map to access texels in a direct texture providing an image when viewed through said viewing surface; and

displaying an image rendered based on said accessed direct texture.

18. The method as in claim 17 further including copying out an image from a frame buffer into said direct texture.

19. A system for producing computer-generated fluid effects comprising:

a user input device that at least partially specifies a viewing surface location and direction in a virtual 3D world;

an indirect texture map that models image distortion due to a coating on the viewing surface;

a surface modeling component that models a fluid surface using a plurality of surface modeling layers, said surface modeling component dynamically changing the number of said plurality of layers;

a polygon mesh generator that dynamically generates a polygon mesh from said plurality of surface modeling layers based at least in part on said specified viewing surface location and direction; and

an image generator that generates an image of said surface as viewed through said viewing surface and said coating thereon, in response to said dynamically generated polygon mesh and said indirect texture map.