Dynamic view-dependent texture mapping

• US 6,525,731 B1
• Filed: 11/09/1999
• Issued: 02/25/2003
• Est. Priority Date: 11/09/1999
• Status: Expired due to Term

• Current Assignee: Activision Publishing Incorporated (Microsoft Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Horn, William P., Suits, Frank, Klosowski, James T.
• Primary Examiner(s): Zimmerman, Mark
• Assistant Examiner(s): Sealey, Lance W
• Application Number:
  US09/436,904
• Time in Patent Office: 1,204 Days
• Field of Search: 345/419, 345/426, 345/428, 345/619, 345/427, 345/421
• US Class Current: 345/427
• CPC Class Codes: G06T 15/04 Texture mapping

Abstract

A system for providing interactive views of 3-dimensional models with surface properties is disclosed. The system provides a compact representation of a 3D model and its surface features and provides for efficiently viewing and interacting with the model using dynamically switched texture maps. The compact representation is beneficial for transmission of the model across a network as well as for local storage of the model in the computer memory. The dynamically switched texture maps allow for more accurate surface details on the 3D model, as well as speedy interaction between a user and the 3D model.

Claims

1. A computer imaging system having at least one central processing unit (CPU), at least one memory, and at least one network interface to at least one network, the computer imaging system comprising:

a) at least one model stored in at least one of the memories, the model having geometric features and surface features;

b) a means for creating a number of camera views around the models;

c) a means for creating a 2D rendered image of the models for each camera view; and

d) a means for storing the geometric features, the 2D rendered images, and the respective camera views in at least one of the memories.

2. A computer imaging system as in claim 1, where the stored geometric features, 2D rendered images, and respective camera views are transmitted over at least one network connection.

3. A computer imaging system having at least one central processing unit (CPU), at least one memory, the computer imaging system comprising:

a) a means for receiving a geometric representation of a 3D model, at least one camera orientation and a 2D rendered image of the 3D model for each camera orientation;

b) a means for determining which portion of the 3D model'"'"'s geometric representation, in each of the 2D rendered images, are fully visible, not visible and partially visible from one or more of the respective camera orientations;

c) a means for creating a “

not visible”

location indicator that will indicate “

not fully visible”

;

d) a means for calculating, for each 2D rendered image, one or more texture coordinates of each corner of each portion of the 3D model'"'"'s geometric representation and substituting the “

not visible”

location indicator for the portions of the 3D model'"'"'s geometric representation that are not visible and partially visible, to create a texture map of a 3D textured object; and

e) a display that displays the 3D textured object.

4. A computer imaging system as in claim 3, wherein the display dynamically selects, as a user is interactively viewing the 3D model, a texture map to use based upon a camera orientation closest to a current view direction of the user.

5. A computer imaging system for producing an interactive image of a three-dimensional (3D) model, comprising:

a storage means for storing 3D models, said 3D models having geometric features;

a means for determining at least one viewpoint of one of the 3D models;

a rendering means for rendering images of the 3D model from each of said viewpoints;

a processing means for pre-processing the at least one rendering, the at least one viewpoint corresponding to said at least one rendering, and the geometric features of the 3D model, wherein the processing means includes;

a means for applying a visibility algorithm to determine, for each viewpoint, which portions of the 3D model'"'"'s geometric features are fully visible, partially occluded, or backfacing;

a means for mapping, for each viewpoint, the fully visible portions of the 3D model into texture coordinates corresponding to the viewpoint; and

a means for mapping, for each viewpoint, the remaining geometry to an assigned pixel to represent the lack of texture image data for the viewpoint in the corresponding rendering;

a display means for displaying the 3D model;

an input means for at least one user to interact with the 3D model for allowing the user to select a viewpoint of the 3D model;

a means for determining which viewpoint approximates a viewpoint of the at least one user; and

a means for creating an image to display on the display means, said image created from the geometric features of the 3D model, the rendering and the mapping of the fully visible portions and the remaining geometry corresponding to the view point which approximates the viewpoint of the at least one user.

6. The computer imaging system of claim 5, further comprising:

a compression and simplification means for compressing and simplifying said geometric features before the processing means pre-processes said geometric features.

7. The computer imaging system of claim 5, wherein the processing means further comprises a means for assigning at least one pixel of an empty region in the rendering to be the assigned pixel, and assigning the assigned pixel to a color to represent the lack of texture image data for the viewpoint corresponding to said rendering.

8. The computer imaging system of claim 5, wherein the means for creating an image to display on the display means further comprises:

a means to request from said rendering means additional renderings from additional camera viewpoints.

9. The computer imaging system of claim 5, wherein said computer imaging system comprises a client/server computer system.

10. The computer imaging system of claim 9, wherein said client/server computer system comprises:

at least one server for preparing 3D model data to be sent to the client, comprising said means for determining at least one viewpoint and said rendering means; and

at least one client for displaying the 3D model and interacting with at least one user, comprising said processing means, said displaying means, said input means, said means for determining which said at least one viewpoint corresponding to said at least one rendering approximates a viewpoint of the at least one user, and said means for creating an image to display on the display means.

11. The computer imaging system of claim 10, wherein said server produces the renderings without shading and the client provides shading.

12. The computer imaging system of claim 10, wherein said 3D model further has surface features and said server produces the renderings with faceted shading and the client disables shading and illumination, thereby displaying the 3D model with original surface features and shading.

13. A computer-based interactive three-dimensional (3D) imaging method comprising the steps of:

a) storing one or more 3D models, the 3D models having geometric features and surface features;

b) selecting a plurality of viewpoints on a 3D model taken from storage;

c) producing a 2D rendering of the 3D model for each of said plurality of viewpoints;

d) transmitting the geometry, the renderings, and respective viewpoints to an imaging means;

e) producing an image of the 3D model for each respective viewpoint based on the geometric features and rendering on the imaging means;

f) selecting an initial viewpoint and displaying its corresponding image on a display means;

g) interacting with at least one user through an input means, said input means allowing the at least one user to change the at least one user'"'"'s viewpoint on the 3D model;

h) selecting which of said plurality of viewpoints approximates a user'"'"'s current viewpoint;

i) disabling shading and illumination at the imaging means when the surface features include shading; and

j) displaying the image corresponding to the selected viewpoint on the display means.

14. The computer-based interactive three-dimensional (3D) imaging method of claim 13, further comprising the step of:

compressing and simplifying said geometric features.

15. The computer-based interactive three-dimensional (3D) imaging method of claim 13, further comprising the steps of:

applying a visibility algorithm to determine which portions of the 3D model'"'"'s geometric features are fully visible, partially occluded, or backfacing;

assigning at least one pixel of an empty region in the rendering to a color to represent the lack of texture image data for the viewpoint corresponding to said rendering;

mapping the fully visible portions of the 3D model into texture coordinates corresponding to the current at least one user viewpoint; and

mapping the remaining geometry to the at least one assigned pixels.

16. The computer-based interactive three-dimensional (3D) imaging method of claim 13, further comprising the step of:

performing step (c) when additional renderings are required.

17. The computer-based interactive three-dimensional (3D) imaging method of claim 13, further including the step of performing steps a-j on a plurality of processing means in at least one network.

18. A computer imaging system for producing an interactive image of a three-dimensional (3D) model, said computer imaging system comprising:

a processing means for pre-processing at least one 2D rendering of a 3D model, a viewpoint corresponding to each of said at least one 2D rendering, and geometric features of the 3D model, said processing means including;

a means for applying a visibility algorithm to determine, for each viewpoint, which portions of the 3D model'"'"'s geometric features are fully visible, partially occluded, or backfacing;

a means for mapping, for each viewpoint, the fully visible portions of the 3D model into texture coordinates corresponding to the viewpoint; and

a means for mapping, for each viewpoint, the remaining geometry to an assigned pixel to represent the lack of texture image data for the viewpoint in the corresponding rendering;

a display means for displaying the 3D model;

an input means for at least one user to interact with the 3D model;

a means for determining which viewpoint of said at least one viewpoint approximates a viewpoint of the at least one user; and

a means for creating an image to display on the display means, said image created from the geometric features of a 3D model and the at least one 2D rendering and the mapping of the fully visible portions and remaining geometry corresponding to the viewpoint which approximates the viewpoint of the at least one user.

19. A computer imaging system for producing an interactive image of a three-dimensional (3D) model, said computer imaging system comprising:

a means for applying a visibility algorithm to determine which portions of a 3D model'"'"'s geometric features are fully visible, partially occluded, or backfacing in a rendering of the 3D model;

a means for assigning at least one pixel of an empty region in the rendering to a color to represent the lack of texture image data for the viewpoint corresponding to said rendering;

a means for mapping the fully visible portions of the 3D model into texture coordinates corresponding to a current user viewpoint; and

a means for mapping the remaining geometry to the at least one assigned pixels.

20. A computer-based interactive three-dimensional (3D) imaging method, said method being tangibly embodied in a program of instructions readable and executable by a machine, comprising the steps of:

a) storing one or more 3D models, the 3D models having geometric features and surface features including shading;

b) selecting a plurality of viewpoints on a 3D model taken from storage;

c) producing a 2D rendering of the 3D model for each of said plurality of viewpoints;

d) transmitting the geometry, the renderings, and respective viewpoints to an imaging means;

e) producing an image of the 3D model for each respective viewpoint based on the geometric features and rendering on the imaging means;

f) selecting an initial viewpoint and displaying its corresponding image on a display means;

g) interacting with at least one user through an input means, said input means allowing the at least one user to change the at least one user'"'"'s viewpoint on the 3D model;

h) selecting which of said plurality of viewpoints approximates a user'"'"'s current viewpoint; and

i) disabling shading and illumination at the imaging means when the surface features include shading; and

j) displaying the image corresponding to the selected viewpoint on the display means.