Generating image data

• US 6,411,297 B1
• Filed: 03/03/1999
• Issued: 06/25/2002
• Est. Priority Date: 03/03/1999
• Status: Expired due to Term

• Current Assignee: Autodesk, Inc.
• Original Assignee: Discreet Logic, Inc. (Autodesk, Inc.)
• Inventors: Tampieri, Filippo
• Primary Examiner(s): Nguyen, Phu K.
• Application Number:
  US09/261,143
• Time in Patent Office: 1,210 Days
• Field of Search: 345/419, 345/426, 345/423, 345/427, 345/428
• US Class Current: 345/426
• CPC Class Codes: G06T 15/55 Radiosity

Abstract

A multi-resolution representation of a radiosity equation for a scene is constructed. The scene comprises object elements and steps are performed to identify specialised cluster elements by associating object elements having a characterising relationship. Elements are linked and/or meshed in response to an estimate of error of light transmission between the elements. The linking includes the process of calculating a form factor and when linking a specialised cluster, the form factor is calculated with reference to the characterising relationship. The characterising relationship may be, for example, near co-planarity and in this way the overall processing and calculation requirements are reduced.

Claims

1. A method of constructing a multi-resolution representation of a radiosity equation for a scene, wherein said scene comprises object elements;

comprising the steps of;

identifying specialised cluster elements by associating object elements having a characterising relationship; and

linking and/or meshing elements in response to an estimate of error of light transmission between elements;

wherein

said linking includes calculating a form factor; and

when linking a specialised cluster, said form factor is calculated with reference to said characterising relationship.

2. A method according to claim 1, further including the step of identifying generalised cluster elements by associating object elements in close proximity to each other;

and

when linking a cluster, a procedure for calculating said form factor is selected in response to said cluster type.

3. A method according to claim 1, wherein said characterising relationship relates to light reflectance.

4. A method according to claim 1, wherein said characterising relationship is that of near co-planarity.

5. A method according to claim 1, wherein said characterising relationship is determined with reference to scene graph data.

6. A method of constructing a multi-resolution representation of a radiosity equation for a scene, wherein said scene comprises object elements;

comprising the steps of

identifying specialised cluster elements by associating object elements having a characterising relationship;

identing general cluster elements by associating object elements according to proximity; and

linking and/or meshing elements in response to an estimate of error of light transmission between elements;

wherein

said linking step includes calculating a form factor; and

when linking a cluster, selecting a method of form factor calculation in response to the cluster type.

7. A method according to claim 6, wherein specialised clusters are identified prior to general clusters.

8. A method according to claim 7, wherein specialised dusters are analysed for consideration as individual elements in general clusters.

9. A method of generating image data from scene data, wherein said scene data includes objects considered as elements;

an object has a surface that may be subdivided into a mesh, such that each component of said object is considered as an element; and

a plurality of said objects may be grouped into a cluster of objects, also considered as an element;

comprising the steps of

identifying specialised clusters according to object characteristics;

identifying general dusters according to object proximity;

meshing object surfaces in response to a process of constructing a multi-resolution representation of the radiosity equation for said scene; and

solving said radiosty equation.

10. A method according to claim 9, wherein said image data is rendered from a view determined in response to data from a virtual set.

11. Apparatus for constructing a multi-resolution representation of a radiosity equation for a scene, including

storage means for storing instructions for processing means and data representing said scene;

wherein

said scene comprises object elements, and said instructions in said storage means are arranged to configure said processing means to perform steps of;

identifying specialised cluster elements by associating object elements having a characterising relationship; and

linking and/or meshing elements in response to an estimate of error of light transmission between elements in which

said linking includes calculating a form factor; and

when linking a specialised cluster, said form factor is calculated with reference to said characterising relationship.

12. Apparatus according to claim 11, further configurable to perform the step of identifying generalised cluster elements by associating object elements in close proximity to each other;

and

when linking a cluster, a procedure for calculating said form factor is selected in response to said cluster type.

13. Apparatus according to claim 11, wherein elements in said specialised cluster have a characterising relationship characterised in that elements have a common characteristic that relates to light reflectance.

14. Apparatus according to claim 11, wherein said characterising relationship is that of near co-planarity.

15. Apparatus according to claim 11, wherein said characterising relationship is determined with reference to scene graph data.

16. Apparatus for constructing a multi-resolution representation of a radiosity equation for a scene, comprising

storage means for storing instructions for processing means and data representing said scene;

wherein

said scene comprises object elements, and said instructions in said storage means are arranged to configure said processing means to perform steps of;

identifying specialised cluster elements by associating object elements having a characterising relationship;

identifying general cluster elements by associating object elements according to proximity; and

linking and/or meshing elements in response to an estimate of error of light transmission between elements;

wherein

said linking includes calculating a form factor; and

when linking a cluster, selecting a method of form factor calculation in response to the cluster type.

17. Apparatus according to claim 16, wherein specialised clusters are identified prior to general clusters.

18. Apparatus according to claim 17, wherein specialised clusters may be analysed for consideration as individual elements in general clusters.

19. Apparatus for generating image data from scene data, including processing means, and storage means for storing instructions for processing means and data representing said scene, wherein

said scene includes objects considered as elements;

at least one of said object has a surface that may be subdivided into a mesh, each component of which being considered as an element; and

a plurality of said objects may be grouped into a cluster of objects, also considered as an element;

wherein

said instructions configure said processing means to perform the steps of;

identifying specialised dusters according to object characteristics;

identifying general clusters according to object proximity

meshing object surfaces in response to a process of constructing a multi-resolution representation of a radiosity equation for said scene; and

solving said radiosity equation.

20. Apparatus according to claim 19, further including interface means, wherein said image data is rendered from a view determined in response to data, from a virtual set.

21. In a virtual set, in which real foreground images are combined with synthesised background images in real-time, means configured to generate said background image data, wherein

a multi-resolution representation of a radiosity equation for a scene is constructed, including

storage means for storing instructions for processing means and data representing said scene;

wherein

said scene comprises object elements, and said instructions in said storage means are arranged to configure said processing means to perform steps of;

identifying specialised cluster elements by associating object elements having a characteristic relationship; and

linking and/or meshing elements in response to an estimate of error of light transmission between elements;

in which

said linking includes calculating a form factor; and

when linking a specialised cluster, said form factor is calculated with reference to said characterising relationship.

22. Apparatus according to claim 21, further configurable to perform the step of identifying generalised cluster elements by associating object element in close proximity to each other;

and

when linking a cluster, a procedure for calculating said form factor is selected in response to said cluster type.

23. Apparatus according to claim 21, wherein elements in said specialised cluster have a characterising relationship characterised in that elements have a common characteristic that relates to light reflectance.

24. Apparatus according to claim 21, wherein said characterising relationship is that of near co-planarity.

25. Apparatus according to claim 21, wherein said characterising relationship to determined with reference to scene graph data.

26. A computer-readable medium having computer-readable instructions executable by a computer such that said computer peforms the steps of:

identifying specialised cluster elements by associating object elements having a characteristic relationship; and

linking and/or meshing elements in response to an estimate of error of light transmission between said elements;

wherein

said linking includes calculating a form factor; and

when linking a specialised cluster, said form factor is calculated with reference to said characterising relationship, thereby constructing a multi-resolution representation of a radiosity equation for a scene.

27. A computer-readable medium according to claim 26, wherein said instructions are executed by said computer so as to identify generalised cluster elements by associating object elements in close proximity to each other;

and

when linking a cluster, a procedure is preformed for calculating said form factor selected in response to said cluster type.

28. A computer-readable medium according to claim 26, wherein said instructions are executed by said computer such that said characterising relationship related to light reflectance.

29. A computer-readable medium according to claim 26, wherein said instructions are executed by said computer such that said characterising relationship is that of near co-planarity.

30. A computer-readable medium according to claim 26, wherein said instructions are executed by said computer such that said characterising relationship is determined with reference to scene graph data.