Method and system for efficient modeling of specular reflection

• US 9,619,920 B2
• Filed: 01/31/2013
• Issued: 04/11/2017
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: Armstrong Word Industries Incorporated, Armstrong World Industries Incorporated, Dirtt Environmental Solutions
• Original Assignee: ICE Edge Business Solutions Ltd.
• Inventors: Howell, Joseph S.
• Primary Examiner(s): Crawford, Jacinta M
• Assistant Examiner(s): DOAN, PHUC N
• Application Number:
  US14/110,910
• Publication Number:
  US 20150325035A1
• Time in Patent Office: 1,531 Days
• CPC Class Codes: G06T 15/06 Ray-tracing
• CPC Class Codes: G06T 15/50 Lighting effects
• CPC Class Codes: G06T 15/80 Shading
• CPC Class Codes: G06T 2215/12 Shadow map, environment map

Abstract

Systems, methods, and apparatus allow for the real-time rendering of specular effects within a three-dimensional model. At least one implementation allows a user to create a map that comprises a representation of at least one light source within a three-dimensional model. Furthermore, at least one implementation casts a viewpoint ray to an object surface point, wherein the viewpoint ray comprises a ray extending from a user perspective within the three-dimensional model. Additionally, at least one implementation casts a reflection ray of the viewpoint ray. Further, at least one implementation identifies an intersection point between the reflection ray and the map. Still further, at least one implementation calculates the specular reflection of the object surface point based on the intersection point.

Claims

1. In a computerized architectural design environment in which a design program is loaded into memory and processed at a central processing unit, a computer-implemented method for rendering a specular effect within a three-dimensional model, the method comprising:

creating a map that comprises a representation of at least one light source within the three-dimensional model, wherein;

the at least one light source represented in the map is represented by at least one specular intensity gradient that comprises an attenuating gradient that is determined at least in part by a particular reflective surface type, and

the map comprises two or more specular intensity gradients with different rates of attenuation;

casting a viewpoint ray to an object surface point, wherein the viewpoint ray comprises a ray extending from a user perspective within the three-dimensional model;

casting a reflection ray of the viewpoint ray;

identifying an intersection point between the reflection ray and the map, wherein the intersection point comprises a particular specular intensity gradient value based upon at least one of the two or more specular intensity gradients that is determined at least in part by the particular reflective surface type;

calculating a specular effect on the object surface point based on the intersection point between the reflection ray and the map, wherein the specular effect is calculated at least in part based upon the particular specular intensity gradient value; and

displaying the map that comprises the representation of the at least one light source within the three-dimensional model.

2. The method as in claim 1, wherein the specular intensity gradient on the map decreases as a distance between a location of the at least one light source and a representation of the at least one light source on the map increases.

3. The method as in claim 1, wherein the specular intensity gradient is defined by a 3-D Gaussian or 3-D cosine function.

4. The method as in claim 1, wherein the specular intensity gradient depends on the brightness of the at least one light source.

5. The method as in claim 1, further comprising displaying the map that comprises the representation of the at least one light source within the three-dimensional model.

6. The method as in claim 1, wherein the particular specular intensity gradient value is a vector of R, G, B values.

7. The method as in claim 1, wherein the particular specular intensity gradient value is a vector of C, M, Y, K values.

8. In a computerized architectural design environment in which a design program is loaded into memory and processed at a central processing unit, a computer-implemented method for rendering a specular effect within a three-dimensional model, the method comprising:

rendering a three-dimensional model, the three-dimensional model comprising at least one light source;

creating two or more maps of a plane within the three-dimensional model, the two or more maps each comprising a specular intensity gradient representation of the at least one light source;

creating a first attenuating gradient of specular intensity on a first map of the two or more maps, the first attenuating gradient being calculated based upon a first surface reflectivity value;

creating a second attenuating gradient of specular intensity on a second map of the two or more maps, the second attenuating gradient being calculated based upon a second surface reflectivity value, which is different from the first surface reflectivity value;

casting a first ray from a rendered surface within the three-dimensional model to the first map;

identifying a first intersection point between the first ray and the first attenuating gradient of specular intensity on the first map of the two or more maps;

casting a second ray from the rendered surface within the three-dimensional model to the second map;

identifying a second intersection point between the second ray and the second attenuating gradient of specular intensity on the second map of the two or more maps;

determining that a surface reflectivity value of the rendered surface within the three-dimensional model is between the first surface reflectivity value and the second surface reflectivity value; and

calculating a specular reflection of the rendered surface based on the intersection points by interpolating between information stored at the first intersection point and information stored at the second intersection point.

9. The method as in claim 8, wherein the specular intensity gradient representation of the at least one light source comprises an attenuating gradient that is determined at least in part by a reflective surface type of the surface.

10. The method as in claim 8, wherein the specular intensity gradient value depends on a distance between a light source and the plane.

11. The method as in claim 8, wherein an effect of two or more light sources on the specular intensity gradient value is cumulative.

12. The method as in claim 8, wherein the plane is substantially parallel to the floor and/or ceiling in the three-dimensional model.

13. The method as in claim 8, wherein the at least one light source is on the plane, and the at least one representation of the at least one light source on the plane is equivalent to the at least one light source'"'"'s normal projection on the plane.

14. The method as in claim 8, further comprising creating two or more planes, wherein each plane comprises at least one representation of one or more light sources that intersects with each respective plane.

15. The method as in claim 8, further comprising determining specular reflection values for additional points on the surface of the object by interpolation of specular reflection values of two or more object surface points.

16. A computer system for efficiently rendering specular effect, comprising:

one or more processors; and

one or more computer-readable media having stored thereon executable instructions that when executed by the one or more processors configure the computer system to perform at least the following;

create a map that comprises a representation of at least one light source within a three-dimensional model, wherein;

the at least one light source represented in the map is represented by at least one specular intensity gradient that comprises an attenuating gradient that is determined at least in part by a particular reflective surface type, and

that map comprises two or more specular intensity gradients with different rates of attenuation;

cast a viewpoint ray to an object surface point, wherein the viewpoint ray comprises a ray extending from a user perspective within the three-dimensional model casting a reflection ray of the viewpoint ray;

identify an intersection point between the reflection ray and the map, wherein the intersection point comprises a particular gradient value based upon at least one of the two or more specular intensity gradients that is determined at least in part by the particular reflective surface type;

calculate the specular reflection of the object surface point based on the intersection point between the reflection ray and the map, wherein the specular effect is calculated at least in part based upon the particular gradient value; and

display the map that comprises the representation of the at least one light source within the three-dimensional model.