GRASP SIMULATION OF A VIRTUAL OBJECT

• US 20110261083A1
• Filed: 04/27/2010
• Published: 10/27/2011
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Wilson, Andrew D.
• Granted Patent: US 8,576,253 B2
• Time in Patent Office: Days
• US Class Current: 345/676
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user

Abstract

The claimed subject matter provides a system and/or a method for simulating grasping of a virtual object. Virtual 3D objects receive simulated user input forces via a 2D input surface adjacent to them. An exemplary method comprises receiving a user input corresponding to a grasping gesture that includes at least two simulated contacts with the virtual object. The grasping gesture is modeled as a simulation of frictional forces on the virtual object. A simulated physical effect on the virtual object by the frictional forces is determined. At least one microprocessor is used to display a visual image of the virtual object moving according to the simulated physical effect.

Claims

1. A computer-implemented method of simulating grasping of a virtual object, comprising:

receiving a user input corresponding to a grasping gesture that includes at least two simulated contacts with the virtual object;

modeling the grasping gesture as a simulation of frictional forces on the virtual object;

determining a simulated physical effect on the virtual object by the frictional forces; and

displaying, using at least one microprocessor, a visual image of the virtual object moving according to the simulated physical effect.

2. The computer-implemented method recited in claim 1, comprising representing the frictional forces with a plurality of persistent particle proxies.

3. The computer-implemented method recited in claim 1, wherein each of the at least two simulated contacts is represented as a contour that corresponds to an area of interaction between an input object and the virtual object.

4. The computer-implemented method recited in claim 1, wherein each of the at least two simulated contacts is modeled as a connected component.

5. The computer-implemented method recited in claim 1, wherein the frictional forces are modeled as exerting normal forces on a side surface of the virtual object.

6. The computer-implemented method recited in claim 1, wherein an incursion of one or more of the at least two simulated contacts into a region within the virtual object is modeled as a force applied to the virtual object that increases in proportion to a distance of the incursion.

7. The computer-implemented method recited in claim 1, wherein the simulation of physical effect comprises at least one of a force, a mass, a velocity or a friction.

8. The computer-implemented method recited in claim 1, comprising modeling a subsequent user input by determining whether persistent particle proxies corresponding to the at least two contacts are still present in the subsequent user input.

9. The computer-implemented method recited in claim 8, comprising determining whether the subsequent user input comprises additional persistent particle proxies.

10. The computer-implemented method recited in claim 8, comprising:

determining a subset of the plurality of persistent particle proxies that no longer has an effect on movement of the virtual object; and

removing the subset of the plurality of persistent particle proxies from further simulation.

11. The computer-implemented method recited in claim 8, wherein each of the at least two simulated contacts is modeled as a stack of persistent particle proxies.

12. A system that facilitates a simulated interaction of an input object with a virtual object, comprising:

a detection component that detects multiple inputs by the input object, the multiple detected inputs enabling a simulated physical interaction of the multiple detected inputs with the virtual object; and

a physics engine that models each of the multiple detected inputs as persistent particle proxy object to employ physics-based principles into the simulated interaction with the virtual object in order to model an effect of at least one of a force, a mass, a velocity or a friction on the virtual object.

13. The system recited in claim 12, wherein each of the multiple detected inputs is represented as a contour that corresponds to an area of interaction between an input object and the virtual object.

14. The system recited in claim 12, wherein the persistent particle proxy objects are modeled as exerting a normal force on a side surface of the virtual object.

15. The system recited in claim 12, wherein an incursion of one or more of the multiple detected inputs into a region within the virtual object is modeled as a force that increases in proportion to a distance of the incursion.

16. The system recited in claim 12, wherein a subsequent user input is modeled by determining whether persistent particle proxy objects corresponding to the at least two contacts are still present in the subsequent user input relative to an initial user input.

17. The system recited in claim 16, wherein the subsequent user input is modeled by determining whether the subsequent user input encompasses additional persistent particle proxy objects relative to an initial user input.

18. The system recited in claim 17, wherein the subsequent user input is modeled by determining a subset of the persistent particle proxy objects that no longer has an impact on the virtual object and wherein the subset of the persistent particle proxy objects that no longer have an impact on the virtual object is no longer used in further simulation of interaction with the virtual object.

19. A computer-implemented method of simulating motion of a virtual object, comprising:

receiving a first user input of at least two simulated contacts with the virtual object;

defining a first plurality of persistent particle proxies to represent the at least two simulated contacts of the first user input;

modeling a first frame of a simulation by representing each of the at least two simulated contacts of the first user input as the first plurality of persistent particle proxies;

receiving a second user input of at least two simulated contacts with the virtual object;

defining a second plurality of persistent particle proxies to represent the second user input by determining whether any of the plurality of persistent particle proxies present in the first user input is also present in the second user input, by determining whether any of the plurality of persistent particle proxies present in the first user input is not present in the second user input, and by determining whether the second user input comprises any persistent particle proxies that were not present in the first user input;

modeling a second frame of the simulation by representing each of the at least two simulated contacts of the second user input as the second plurality of persistent particle proxies; and

displaying, using at least one microprocessor, a visual image of the virtual object in which a position of the virtual object changes according to a simulation of a difference in physical forces represented by the second plurality of persistent particle proxies relative to the first plurality of persistent particle proxies.

20. The computer-implemented method recited in claim 19, comprising using a raycasting operation to determine a location on the virtual object for the persistent particle proxies that are present in the second user input but not the first user input.