CONSTRAINED NAVIGATION IN A THREE-DIMENSIONAL (3D) VIRTUAL ARENA

• US 20080294299A1
• Filed: 05/25/2007
• Published: 11/27/2008
• Est. Priority Date: 05/25/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Amsterdam, Jeffrey D., Curry, Edward P.
• Granted Patent: US 8,326,442 B2
• Time in Patent Office: Days
• US Class Current: 700/303
• CPC Class Codes: H04N 13/275 from 3D object models, e.g. computer-generated stereoscopic image signals

Abstract

This disclosure describes a method for camera/user view navigation about enclosed 3D environment (e.g., the inside of a sports stadium or arena). The navigation system constrains the user view (camera) to a (pre-defined) guide based on the shape and size of the interior area which is the focus of the 3D virtual world. In the case of an arena this would generally be the playing surface. The user can easily control the camera movement on this guide with traditional up/down and left/right controls. These controls could be implemented as buttons within the application, keyboard controls, or mouse controls.

Claims

1. A method for constrained navigation in a three dimensional (3D) virtual arena, comprising:

creating a guide for navigating a camera about the 3D virtual arena by defining a set of parameters to define a series of ellipses around a surface area associated with the 3D virtual arena, the set of parameters comprising a start Y value;

determining a default position for the camera by calculating a start X value and a start Z value for the series of ellipses; and

positioning the camera at the default position using the start X value, the start Y value and the start Z value.

2. The method of claim 1, further comprising repositioning the camera based on a user navigation along the guide.

3. The method of claim 2, the user navigation comprising a discrete movement along an X-axis.

4. The method of claim 3, further comprising:

changing a degree of rotation value by rotation increment value based on the discrete movement;

calculating Radians from the degree of rotation value after the changing;

calculating a new start X value on a elliptical plane associated with series of ellipses;

calculating a new start Z value on the elliptical plane; and

the repositioning comprising;

repositioning the camera using the new start X value and the new start Z value, and

pointing the camera towards a center of the surface area.

5. The method of claim 4, the new start X value being calculated using the function (minor axis value)*cos(Radians), and the new start Z value being calculated using the function:

(major axis value)*cos(Radians).

6. The method of claim 2, the user navigation comprising a discrete movement along a Y-axis.

7. The method of claim 6, further comprising:

if a current camera Y value is above the start Y value, creating a negative multiplier;

if the current camera Y value is below the start Y value, creating a positive multiplier;

if the current camera Y value is equal to the start Y value, resetting a major axis value and a minor axis value to original values;

obtaining a temporary Y value that is an elevation increment value above or below a current Y position based on movement along the Y-axis;

if the temporary Y value is less than a maximum height value and more than a minimum height value, updating the major axis value and the minor axis value by;

(the major axis value+(the elevation increment value*a multiplier*a direction value)), where a direction of the movement is considered negative for downward movement and positive for upward movement;

setting the current camera Y value to the temporary Y value and calculating a new X value and a new Z value based on new axes; and

repositioning the camera.

8. The method of claim 1, the set of parameters further comprising:

a surface length value corresponding to a length of the surface area which is a focus of a view of the camera;

a surface width value corresponding to a width of the surface area which is the focus of the view of the camera;

a major axis value comprising;

(a multiplier*the surface length value), the major axis value corresponding to a major axis of a largest of the set of ellipses around the surface area;

a minor axis value comprising;

(the multiplier*the surface width value), the minor axis value corresponding to a minor axis of a largest of the set of ellipses around the surface area;

a degree of rotation value corresponding to rotation around an ellipse for the default position;

the start Y value, the start Y value corresponding to a height for the default position;

a maximum height value corresponding to a maximum height of the camera;

a minimum height value corresponding to a minimum height of the camera;

an elevation increment value corresponding to a change in height of the camera from the default position;

a rotation increment value corresponding to a change in degrees that the camera moves around the set of ellipses for each discrete movement;

an elevation step value comprising;

(maximum height value/the elevation increment value) the elevation step value corresponding to a quantity of discrete ellipses that exist between the surface area and the maximum height of the camera;

an elevation major increment value comprising;

(the major axis value/the elevation step value), the elevation major increment value corresponding to a change in axis for each elevation increment value; and

an elevation minor increment value comprising;

(the minor axis value/the elevation step value), the elevation minor increment value also corresponding to a change in axis for each elevation increment value.

9. A system for constrained navigation in a three dimensional (3D) virtual arena, comprising:

a module for creating a guide for navigating a camera about the 3D virtual arena by defining a set of parameters to define a series of ellipses around a surface area associated with the 3D virtual arena, the set of parameters comprising a start Y value;

a module for determining a default position for the camera by calculating a start X value and a start Z value for the series of ellipses; and

a module for positioning the camera at the default position using the start X value, the start Y value and the start Z value.

10. The system of claim 9, a module for repositioning the camera based on a user navigation along the guide.

11. The system of claim 10, the user navigation comprising a discrete movement along an X-axis.

12. The system of claim 11, the module for repositioning being configured to:

change a degree of rotation value by rotation increment value based on the discrete movement;

calculate Radians from the degree of rotation value after the change;

calculate a new start X value on a elliptical plane associated with series of ellipses;

calculate a new start Z value on the elliptical plane;

reposition the camera using the new start X value and the new start Z value, and

point the camera towards a center of the surface area.

13. The system of claim 12, the new start X value being calculated using the function (minor axis value)*cos(Radians), and the new start Z value being calculated using the function:

(major axis value)*cos(Radians).

14. The system of claim 10, the user navigation comprising a discrete movement along a Y-axis.

15. The system of claim 14, the module for repositioning being configured to:

if a current camera Y value is above the start Y value, create a negative multiplier;

if the current camera Y value is below the start Y value, create a positive multiplier;

if the current camera Y value is equal to the start Y value, reset a major axis value and a minor axis value to original values;

obtain a temporary Y value that is an elevation increment value above or below a current Y position based on movement along the Y-axis;

if the temporary Y value is less than a maximum height value and more than a minimum height value, update the major axis value and the minor axis value by;

(the major axis value+(the elevation increment value*a multiplier*a direction value)), where a direction of the movement is considered negative for downward movement and positive for upward movement;

set the current camera Y value to the temporary Y value and calculate a new X value and a new Z value based on new axes; and

reposition the camera.

16. The system of claim 9, the set of parameters further comprising:

a surface length value corresponding to a length of the surface area which is a focus of a view of the camera;

a surface width value corresponding to a width of the surface area which is the focus of the view of the camera;

a major axis value comprising;

(a multiplier*the surface length value), the major axis value corresponding to a major axis of a largest of the set of ellipses around the surface area;

a minor axis value comprising;

(the multiplier*the surface width value), the minor axis value corresponding to a minor axis of a largest of the set of ellipses around the surface area;

a degree of rotation value corresponding to rotation around an ellipse for the default position;

the start Y value, the start Y value corresponding to a height for the default position;

a maximum height value corresponding to a maximum height of the camera;

a minimum height value corresponding to a minimum height of the camera;

an elevation increment value corresponding to a change in height of the camera from the default position;

a rotation increment value corresponding to a change in degrees that the camera moves around the set of ellipses for each discrete movement;

an elevation step value comprising;

(maximum height value/the elevation increment value) the elevation step value corresponding to a quantity of discrete ellipses that exist between the surface area and the maximum height of the camera;

an elevation major increment value comprising;

(the major axis value/the elevation step value), the elevation major increment value corresponding to a change in axis for each elevation increment value; and

an elevation minor increment value comprising;

(the minor axis value/the elevation step value), the elevation minor increment value also corresponding to a change in axis for each elevation increment value.

17. A program product stored on a computer readable medium for constrained navigation in a three dimensional (3D) virtual arena, the computer readable medium comprising program code for causing a computer system to:

create a guide for navigating a camera about the 3D virtual arena by defining a set of parameters to define a series of ellipses around a surface area associated with the 3D virtual arena, the set of parameters comprising a start Y value;

determine a default position for the camera by calculating a start X value and a start Z value for the series of ellipses; and

position the camera at the default position using the start X value, the start Y value and the start Z value.

18. The program product of claim 17, the computer readable medium further comprising program code for causing the computer system to reposition the camera based on a user navigation along the guide.

19. The program product of claim 18, the user navigation comprising a discrete movement along an X-axis.

20. The program product of claim 19, the computer readable medium further comprising program code for causing the computer system to:

change a degree of rotation value by rotation increment value based on the discrete movement;

calculate Radians from the degree of rotation value after the change;

calculate a new start X value on a elliptical plane associated with series of ellipses;

calculate a new start Z value on the elliptical plane;

reposition the camera using the new start X value and the new start Z value, and

point the camera towards a center of the surface area.

21. The program product of claim 20, the new start X value being calculated using the function (minor axis value)*cos(Radians), and the new start Z value being calculated using the function:

(major axis value)*cos(Radians).

22. The program product of claim 18, the user navigation comprising a discrete movement along a Y-axis.

23. The program product of claim 22, the computer readable medium further comprising program code for causing the computer system to:

if a current camera Y value is above the start Y value, create a negative multiplier;

if the current camera Y value is below the start Y value, create a positive multiplier;

if the current camera Y value is equal to the start Y value, reset a major axis value and a minor axis value to original values;

obtain a temporary Y value that is an elevation increment value above or below a current Y position based on movement along the Y-axis;

if the temporary Y value is less than a maximum height value and more than a minimum height value, update the major axis value and the minor axis value by;

(the major axis value+(the elevation increment value*a multiplier*a direction value)), where a direction of the movement is considered negative for downward movement and positive for upward movement;

set the current camera Y value to the temporary Y value and calculate a new X value and a new Z value based on new axes; and

reposition the camera.

24. The program product of claim 17, the set of parameters further comprising:

a surface length value corresponding to a length of the surface area which is a focus of a view of the camera;

a surface width value corresponding to a width of the surface area which is the focus of the view of the camera;

a major axis value comprising;

(a multiplier*the surface length value), the major axis value corresponding to a major axis of a largest of the set of ellipses around the surface area;

a minor axis value comprising;

(the multiplier*the surface width value), the minor axis value corresponding to a minor axis of a largest of the set of ellipses around the surface area;

a degree of rotation value corresponding to rotation around an ellipse for the default position;

the start Y value, the start Y value corresponding to a height for the default position;

a maximum height value corresponding to a maximum height of the camera;

a minimum height value corresponding to a minimum height of the camera;

an elevation increment value corresponding to a change in height of the camera from the default position;

a rotation increment value corresponding to a change in degrees that the camera moves around the set of ellipses for each discrete movement;

an elevation step value comprising;

(maximum height value/the elevation increment value) the elevation step value corresponding to a quantity of discrete ellipses that exist between the surface area and the maximum height of the camera;

an elevation major increment value comprising;

(the major axis value/the elevation step value), the elevation major increment value corresponding to a change in axis for each elevation increment value; and

an elevation minor increment value comprising;

(the minor axis value/the elevation step value), the elevation minor increment value also corresponding to a change in axis for each elevation increment value.

25. A method for deploying a system for constrained navigation in a three dimensional (3D) virtual arena, comprising:

deploying a computer infrastructure being operable to;

create a guide for navigating a camera about the 3D virtual arena by defining a set of parameters to define a series of ellipses around a surface area associated with the 3D virtual arena, the set of parameters comprising a start Y value;

determine a default position for the camera by calculating a start X value and a start Z value for the series of ellipses; and

position the camera at the default position using the start X value, the start Y value and the start Z value.