Hierarchical system and method for on-demand loading of data in a navigation system

• US 20080091732A1
• Filed: 10/19/2007
• Published: 04/17/2008
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Aaron Lee, Hauke Schmidt, Tuolin Chen
• Original Assignee: Aaron Lee, Hauke Schmidt, Tuolin Chen
• Inventors: Schmidt, Hauke, Lee, Aaron, Chen, Tuolin
• Granted Patent: US 8,849,859 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/3638 including 3D objects and buildings three dimensional [3D] modelling, e.g. data description of 3D objects G06T17/00; geographic models G06T17/05
• CPC Class Codes: G06T 17/005 Tree description, e.g. octree, quadtree
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 19/003 Navigation within 3D models or images
• CPC Class Codes: G06T 2210/12 Bounding box
• CPC Class Codes: G06T 2210/36 Level of detail
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A system providing three-dimensional visual navigation for a mobile unit includes a location calculation unit for calculating an instantaneous position of the mobile unit, a viewpoint control unit for determining a viewing frustum from the instantaneous position, a scenegraph manager in communication with at least one geo-database to obtain geographic object data associated with the viewing frustum and generating a scenegraph organizing the geographic object data, and a scenegraph renderer which graphically renders the scenegraph in real time. To enhance depiction, a method for blending images of different resolutions in the scenegraph reduces abrupt changes as the mobile unit moves relative to the depicted geographic objects. Data structures for storage and run-time access of information regarding the geographic object data permit on-demand loading of the data based on the viewing frustum and allow the navigational system to dynamically load, on-demand, only those objects that are visible to the user.

Claims

1. A hierarchical data structure, comprising:

a resource-index format to store meta data of a system; and

a level-of-detail format to store actual data of the system, the actual data being loadable on demand.

2. The hierarchical data structure of claim 1, wherein the system includes a mobile navigational system.

3. The hierarchical data structure of claim 1, wherein the resource-index format includes positional information of the system arranged in a hierarchical manner.

4. The hierarchical data structure of claim 1, wherein the resource-index format includes a sequence of tile and bounding box information.

5. The hierarchical data structure of claim 1, wherein the level-of-detail format includes resource object features in multiple levels of detail and a pointer to point to the resource object features.

6. The hierarchical data structure of claim 5, wherein the actual data is arranged to optimize accessing the resource object features.

7. A navigation system, comprising:

at least one resource object;

meta data associated with the system and a position of the at least one resource object, the meta data being arranged in a hierarchical manner; and

actual data associated with the at least one resource object.

8. The navigation system of claim 7, wherein the meta data and the actual data are arranged separately.

9. The navigation system of claim 8, wherein the meta data is arranged in a resource index format and the actual data is arranged in a level-of-detail format.

10. The navigation system of claim 9, wherein the level-of-detail format includes features of the at least one resource object in multiple levels of detail.

11. A navigation system, comprising:

at least one resource object;

meta data to describe a hierarchical relationship between portions of the system and between the at least one resource object and the system; and

actual data to describe the at least one resource object, wherein the meta data and the actual data are arranged separately.

12-21. -21. (canceled)