Method and program for generating a two-dimensional cartoonish picturization of a three-dimensional object

• US 20030222875A1
• Filed: 02/27/2003
• Published: 12/04/2003
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: CELSYS, Inc. (ArtSpark Holdings, Inc.)
• Original Assignee: CELSYS, Inc. (ArtSpark Holdings, Inc.)
• Inventors: Mizuno, Osamu, Kawakami, Yosuke
• Granted Patent: US 7,542,033 B2
• Time in Patent Office: Days
• US Class Current: 345/473
• CPC Class Codes: G06T 15/02 Non-photorealistic rendering

Abstract

A method and computer program are provided for implementing a method for cartoonish picturization by generation from three-dimensional object data. The placement of the three-dimensional object, the view point, and the position of an illumination light source are set. The direction in which the three-dimensional object exists is obtained as mask information, the colors indicating the object are obtained as color information, the distance between the object outer surfaces and the view point is object as distance information, and normal vectors of the outer surfaces are obtained as normal vector information. Based on the mask information, the distance information, and the normal vector information, main lines (61, 71, 76) are plotted (23) as two-dimensional pixels, a based on the color information and a reference value, textures (601, 602, 701, 702) differing about the region of the reference value are applied to achieve visual gradation (24), and the main lines and textures are combined to generate a two-dimensional image that is a cartoonish picturization to be displayed.

Claims

1. A method for generating a cartoonish picturization of a two-dimensional image from three-dimensional object data comprising:

a placement input step accepting an arrangement of a three-dimensional object within a virtual space by an input means;

a view point setting step of accepting the position of a view point within a virtual space by an input means;

a light source configuration step of accepting an attribute of an illumination light source within a virtual space by an input means;

a step of obtaining by a processing means the direction in which a three-dimensional object exists, seen from the view point, as mask information;

a step of obtaining by a processing means a color indicating the three-dimensional object as color information;

a step of obtaining by a processing means a distance between outer surfaces and a view point, as seen from the view point of the three-dimensional object, as distance information;

a step of obtaining by a processing means a normal vector respective to an outer surface in the virtual space as normal vector information;

a step of plotting by a processing means main lines in two-dimensional surface pixels, based on the mask information, distance information, and normal vector information;

a step of visual gradation by a processing means, whereby, based on the color information and a reference value, gradation is applied to surfaces having textures that differ with regard to the reference value in the two-dimensional surface; and

an image displaying step of displaying a composed image by a processing means, the image being synthesized from main lines in the two-dimensional surface and an adopted texture.

2. A method for generating a cartoonish picturization of a two-dimensional image from three-dimensional object data according to claim 1, wherein, in the main line plotting step, the main line representing an outline of the object has a different line width than other main lines.

3. A method for generating a cartoonish picturization of a two-dimensional image from three-dimensional object data according to claim 1, wherein the main line plotting step comprises:

a step of determining by a calculating means a difference value of the distance information using distance information of a current pixel on the two-dimensional surface and distance information of surrounding pixels, and

a step of determining by a calculating means a difference value of the normal vector information using normal vector information of a current pixel on the two-dimensional surface and normal vector information of surrounding pixels, and wherein

the main line plotting step makes a judgment by a calculating means main line plotting, based on the distance difference value and the normal vector information difference value.

4. A method for generating-a cartoonish picturization of a two-dimensional image from three-dimensional object data according to claim 1, wherein

the visual gradation step applies gradation by numerically generated textures generated by a calculating means using a value calculated from the color information and the reference value.

5. A computer program for implementing the method according to claim 1.

6. A computer program for implementing the method according to claim 3.

7. A computer program for implementing the method according to claim 4.

8. A computer program for implementing the method according to claim 4.