Detail-in-context terrain displacement algorithm with optimizations

• US 20060232585A1
• Filed: 04/11/2006
• Published: 10/19/2006
• Est. Priority Date: 04/13/2005
• Status: Active Grant

• Current Assignee: Accessify, LLC (Ascend Innovation Management, LLC)
• Original Assignee: IDELIX Software Inc. (Lat49 Media Inc.)
• Inventors: Tigges, Mark H. A., Montagnese, Catherine
• Granted Patent: US 7,580,036 B2
• Time in Patent Office: Days
• US Class Current: 345/428
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 3/047 Fisheye or wide-angle transformations

Abstract

A method for generating a presentation of a region-of-interest in a terrain data representation for display on a display screen, comprising: translating each point of the representation within a lens bounds to a rotated plane being normal to a vector defined by a position for the region-of-interest with respect to a base plane for the representation and an apex above the base plane, the lens bounds defining a shoulder region at least partially surrounding a focal bounds defining a focal region in which the position is located, each point having a respective height above the base plane; displacing each translated point from the rotated plane by a function of the respective height and a magnification for the focal region, the magnification varying across the shoulder region in accordance with a drop-off function; rotating each displaced point toward a viewpoint for the region-of-interest to maintain visibility of each displaced point and each point of the data representation beyond the lens bounds when viewed from the viewpoint; and, adjusting each rotated point corresponding to the shoulder region to provide a smooth transition to the data representation beyond the lens bounds.

Claims

1. A method for generating a presentation of a region-of-interest in a terrain data representation for display on a display screen, comprising:

translating each point of the representation within a lens bounds to a rotated plane being normal to a vector defined by a position for the region-of-interest with respect to a base plane for the representation and an apex above the base plane, the lens bounds defining a shoulder region at least partially surrounding a focal bounds defining a focal region in which the position is located, each point having a respective height above the base plane;

displacing each translated point from the rotated plane by a function of the respective height and a magnification for the focal region, the magnification varying across the shoulder region in accordance with a drop-off function;

rotating each displaced point toward a viewpoint for the region-of-interest to maintain visibility of each displaced point and each point of the data representation beyond the lens bounds when viewed from the viewpoint; and

,

adjusting each rotated point corresponding to the shoulder region to provide a smooth transition to the data representation beyond the lens bounds.

2. The method of claim 1 and further comprising projecting each adjusted point within the shoulder region, each rotated point within the focal region, and each point of the representation beyond the lens bounds onto a plane in a direction aligned with the viewpoint to produce the presentation.

3. The method of claim 2 and further comprising displaying the presentation on the display screen.

4. The method of claim 3 wherein the translating of each point further comprises determining a maximum translation for a point on the lens bounds and determining a translation for each point within the lens bounds by scaling the maximum translation in accordance with a distance of each point from the lens bounds.

5. The method of claim 3 wherein the function is a product of the magnification and a difference between a magnitude of a vector defined by an origin of the representation with respect to the base plane and the viewpoint and the respective height.

6. The method of claim 3 wherein the rotating of each displaced point further comprises determining an axis of rotation for the rotating from a cross product of a vector defined by an origin of the representation with respect to the base plane and the viewpoint and a vector defined by the origin and the apex.

7. The method of claim 3 wherein the adjusting of each rotated point corresponding to the shoulder region further comprises adding to each rotated point a weighted average of first and second difference vectors scaled by the drop-off function, the first and second difference vectors corresponding to a difference between first and seconds points on the lens bound and corresponding first and second displaced points, respectively, the first and second points being on a line drawn through the rotated point.

8. The method of claim 1 and further comprising approximating the representation with a mesh.

9. The method of claim 1 and further comprising approximating the respective height using height information from surrounding points.

10. A system for generating a presentation of a region-of-interest in a terrain data representation for display on a display screen, the system comprising:

a processor coupled to the display screen; and

,

modules executed by the processor, the modules including;

a module for translating each point of the representation within a lens bounds to a rotated plane being normal to a vector defined by a position for the region-of-interest with respect to a base plane for the representation and an apex above the base plane, the lens bounds defining a shoulder region at least partially surrounding a focal bounds defining a focal region in which the position is located, each point having a respective height above the base plane;

a module for displacing each translated point from the rotated plane by a function of the respective height and a magnification for the focal region, the magnification varying across the shoulder region in accordance with a drop-off function;

a module for rotating each displaced point toward a viewpoint for the region-of-interest to maintain visibility of each displaced point and each point of the data representation beyond the lens bounds when viewed from the viewpoint; and

,

a module for adjusting each rotated point corresponding to the shoulder region to provide a smooth transition to the data representation beyond the lens bounds.

11. The system of claim 10 and further comprising a module for projecting each adjusted point within the shoulder region, each rotated point within the focal region, and each point of the representation beyond the lens bounds onto a plane in a direction aligned with the viewpoint to produce the presentation.

12. The system of claim 11 and further comprising a module for displaying the presentation on the display screen.

13. The system of claim 12 wherein the module for translating each point further comprises a module for determining a maximum translation for a point on the lens bounds and for determining a translation for each point within the lens bounds by scaling the maximum translation in accordance with a distance of each point from the lens bounds.

14. The system of claim 12 wherein the function is a product of the magnification and a difference between a magnitude of a vector defined by an origin of the representation with respect to the base plane and the viewpoint and the respective height.

15. The system of claim 12 wherein the module for rotating each displaced point further comprises a module for determining an axis of rotation for the rotating from a cross product of a vector defined by an origin of the representation with respect to the base plane and the viewpoint and a vector defined by the origin and the apex.

16. The system of claim 12 wherein the module for adjusting each rotated point corresponding to the shoulder region further comprises a module for adding to each rotated point a weighted average of first and second difference vectors scaled by the drop-off function, the first and second difference vectors corresponding to a difference between first and seconds points on the lens bound and corresponding first and second displaced points, respectively, the first and second points being on a line drawn through the rotated point.

17. The system of claim 10 and further comprising a module for approximating the representation with a mesh.

18. The system of claim 10 and further comprising a module for approximating the respective height using height information from surrounding points.