Resource management for rule-based procedural terrain generation

• US 20050264576A1
• Filed: 06/25/2004
• Published: 12/01/2005
• Est. Priority Date: 05/26/2004
• Status: Active Grant

• Current Assignee: Daybreak Game Company, LLC (Enad Global 7 AB)
• Original Assignee: Sony Online Entertainment LLC (Enad Global 7 AB)
• Inventors: Sommers, Anthony L.
• Granted Patent: US 8,368,686 B2
• Time in Patent Office: Days
• US Class Current: 345/543
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects
• CPC Class Codes: G06T 17/05 Geographic models

Abstract

Disclosed are systems and methods for rule-based procedural generation of terrain in real time for a virtual world. By describing the terrain with rules rather than storing the actual geometry data, a drastic savings in terms of memory and disk space is achieved by generating terrain procedurally on the fly in real time when it is necessary. Using the terrain editor tool, the terrain system allows defining and modifying the terrain height, color, shaders, textures, flora, and environment, for example. Additionally, generating the terrain procedurally allows for almost limitless detail by changing the parameters used to create the terrain geometry. These rules can also be added and removed dynamically, leading to terrain modification in real time. In addition, resources are managed for the terrain generation system, such as memory allocation and deallocation.

Claims

1. A method of generating terrain in a virtual world, the method comprising:

receiving in a terrain generator a plurality of procedural rules that define the terrain in a virtual world, wherein each rule affects the generation of a portion of the terrain;

generating terrain in the virtual world in accordance with the plurality of procedural rules by writing data to a buffer for rendering terrain in real time on a visual display; and

providing a resource management policy for deallocating memory allocated to unused or unnecessary portions of the terrain.

2. A method of managing virtual terrain, the method comprising:

allocating memory for a plurality of areas of virtual terrain;

associating a priority level to each of the areas of virtual terrain; and

deallocating memory of the virtual terrain based at least in part on the priority levels of the areas of virtual terrain.

3. The method of claim 2, additionally comprising assigning a priority level to areas the virtual terrain where an avatar is positioned.

4. The method of claim 3, additionally comprising assigning a priority level to areas of the virtual terrain that are proximate to the avatar.

5. The method of claim 4, wherein the priority level assigned to the areas of the virtual terrain where the avatar is positioned is higher than the priority level assigned to the areas of the virtual terrain that are proximate to the avatar.

6. The method of claim 2, wherein one of four priority levels is assigned to the areas of the virtual terrain where an avatar is positioned and to areas of the virtual terrain that are proximate to the avatar.

7. The method of claim 2, wherein deallocating occurs when the number of areas of the virtual terrain exceeds a threshold.

8. A system for managing virtual terrain, the method comprising:

means for allocating memory for a plurality of areas of virtual terrain;

means for associating a priority level to each of the areas of virtual terrain; and

means for deallocating memory of the virtual terrain based at least in part on the priority levels of the virtual terrain.

9. The system of claim 8, additionally comprising means for assigning a priority level to areas the virtual terrain where an avatar is positioned.

10. The system of claim 8, additionally comprising means for assigning a priority level to areas of the virtual terrain that are proximate to an avatar.

11. The system of claim 8, wherein the means for deallocating is invoked when the number of areas of the virtual terrain exceeds a threshold.

12. A program storage device storing instructions that perform the method comprising:

allocating memory for a plurality of areas of virtual terrain;

associating a priority level to each of the areas of virtual terrain; and

deallocating memory of the virtual terrain based at least in part on the priority levels of the virtual terrain.

13. The program storage device of claim 12, additionally comprising assigning a priority level to areas the virtual terrain where an avatar is positioned.

14. The program storage device of claim 12, additionally comprising assigning a priority level to areas of the virtual terrain that are proximate to an avatar.

15. The program storage device of claim 12, wherein deallocating occurs when the number of areas of the virtual terrain exceeds a threshold.

16. A system for managing memory, the system comprising:

a plurality of areas of virtual terrain, each of the areas of virtual terrain having an associated priority level; and

a terrain manager for allocating and deallocating memory for the virtual terrain based at least in part on the priority level.

17. The system of claim 16, wherein areas of the virtual terrain that are near an avatar have a selected priority level.

18. The system of claim 16, wherein areas of the virtual terrain that include an avatar have a selected priority level.

19. A method of managing virtual terrain data, the method comprising:

maintaining a list of unused terrain memory buffers;

in response to a request for a terrain memory buffer, determining whether the list contains at least one terrain memory buffer;

if the set contains at least one terrain memory buffer, providing the terrain memory buffer; and

if the set does not contain at least one terrain memory buffer, requesting an operating system to provide a new terrain memory buffer.

20. The method of claim 19, additionally comprising adding, after use, a terrain memory buffer to the set of unused terrain memory buffers.