System and method for generating and using systems of cooperating and encapsulated shaders and shader DAGs for use in a computer graphics system

• US 6,496,190 B1
• Filed: 07/01/1998
• Issued: 12/17/2002
• Est. Priority Date: 07/02/1997
• Status: Expired due to Term

• Current Assignee: Mental Images GmbH (NVIDIA Corporation)
• Original Assignee: NVIDIA ARC GmbH (NVIDIA Corporation)
• Inventors: Herken, Rolf, Driemeyer, Thomas
• Primary Examiner(s): Nguyen, Phu K.
• Application Number:
  US09/108,596
• Time in Patent Office: 1,630 Days
• Field of Search: 345/426, 345/433, 345/431, 345/425, 345/441, 345/442, 345/443
• US Class Current: 345/619
• CPC Class Codes: G06T 15/005 General purpose rendering architectures
• CPC Class Codes: G06T 15/50 Lighting effects
• CPC Class Codes: G06T 15/80 Shading
• CPC Class Codes: G06T 17/005 Tree description, e.g. octree, quadtree

Abstract

A computer graphics system is described in which a new type of entity, referred to as a “phenomenon,” can be created, instantiated and used in rendering an image of a scene. A phenomenon is an encapsulated shader DAG comprising one or more nodes each comprising a shader, or an encapsulated set of such DAGs which are interconnected so as to cooperate, which are instantiated and attached to entities in the scene which are created during the scene definition process to define diverse types of features of a scene, including features which are useful in rendering. Prior to being attached to a scene, a phenomenon is instantiated by providing values, or functions which are used to define the values, for each of the phenomenon'"'"'s parameters. During scene image generation, a scene image generator operates in a series of phases. During a pre-processing phase, the scene image generator can perform pre-processing operations, such as shadow and photon mapping, multiple inheritance resolution, and the like. The scene image generator may perform pre-processing operations if, for example, a phenomenon attached to the scene includes a geometry shader to generate geometry defined thereby for the scene. During the rendering phase, the scene image generator renders the image. During the post-processing phase, the scene image generator may perform post-processing operations if, for example, a phenomenon attached to the scene includes a shader that defines post-processing operations.

Claims

1. A computer graphics system for generating an image of a scene from a representation to which at least one instantiated phenomenon has been attached, said instantiated phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics system comprising:

A. a pre-processor configured to determine whether the at least one instantiated phenomenon requires a pre-processing operation in connection with said representation, and, if so, performing said pre-processing operation to generate a pre-processed representation of the scene; and

B. a renderer configured to generate a rendered image from said pre-processed representation of the scene.

2. A computer graphics system as defined in claim 1 in which at least one type of shader node is of a geometry shader node type, the pre-processor being configured to perform said pre-processing operation if the at least one shader node is of the geometry shader node type to define geometry for the scene.

3. A computer graphics system as defined in claim 1 in which at least one type of shader node is of a photon shader node type, the pre-processor being configured to perform said pre-processing operation if the at least one shader node is of the photon shader node type to control the paths of photons in the scene and the characteristics of interaction of photons with surfaces of objects in the scene.

4. A computer graphics system as defined in claim 1 in which at least one type of shader node is of a photon emitter shader node type, the pre-processor being configured to perform said pre-processing operation if the at least one shader node is of the photon emitter shader node type to simulate generation of photons by a light source illuminating the scene.

5. A computer graphics system as defined in claim 1 in which at least one type of shader node is of a photon volume shader node type, the pre-processor being configured to perform said pre-processing operation if the at least one shader node is of the photon volume shader node type to simulate interaction of photons from a light source with a three-dimensional volume of space in the scene.

6. A computer graphics system as defined in claim 1 further comprising a post-processor configured to determine whether the at least one instantiated phenomenon requires a post-processing operation in connection with said representation and, if so, performing said post-processing operation.

7. A computer graphics system as defined in claim 1 in which the at least one shader node is of an output shader node type, the post-processor being configured to perform said post-processing operation if the at least one shader node is of he output shader node type.

8. A computer graphics system as defined in claim 7 in which the rendered image comprises a plurality of pixels each associated with a pixel value, the post-processor being configured to perform said post-processing operation in connection with said pixel values.

9. A computer graphics system for generating an image of a scene from a representation to which at least one instantiated phenomenon has been attached, said instantiated phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics system comprising:

A. a renderer configured to generate a rendered image from said representation of the scene; and

B. a post-processor configured to determine whether the at least one instantiated phenomenon requires a post-processing operation in connection with said representation and, if so, performing said post-processing operation.

10. A computer graphics system as defined in claim 9 in which the at least one shader node is of an output shader node type, the post-processor being configured to perform said post-processing operation if the at least one shader node is of he output shader node type.

11. A computer graphics system as defined in claim 10 in which the rendered image comprises a plurality of pixels each associated with a pixel value, the post-processor being configured to perform said post-processing operation in connection with said pixel values.

12. A computer graphics system for enabling an operator to create a phenomenon, the phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics system comprising:

A. a base shader node database configured to store a plurality of base shader nodes, each base shader node including a shader;

B. A phenomenon creator configured to enable said operator to interconnect said base shader nodes from said base shader node database into a DAG, the phenomenon creator verifying that interconnections among said base shader nodes as provided by said operator comprise a DAG.

13. A computer graphics system as defined in claim 12 in which said phenomenon creator stores the phenomenon created by said operator in a phenomenon database.

14. A computer graphics system as defined in claim 12 in which said phenomenon creator is further configured to enable said operator to interconnect said base shader nodes in phenomenon comprising a plurality of cooperating DAGs, in which a shader node in one of said cooperating DAGs, when used during rendering of an image of a scene, provides at least one value which is used in connection with another of said cooperating DAGs.

15. A computer graphics system for enabling an operator to generate, from a phenomenon, an instantiated phenomenon, the phenomenon comprising an encapsulated shader DAG comprising at least one shader DAG including at least one shader node, the computer graphics system comprising:

A. a phenomenon database configured to store said phenomenon, and

B. a phenomenon editor configured to enable said operator to select said phenomenon and provide a value for at least one parameter associated with said at least one shader node.

16. A computer graphics system as defined in claim 15 in which the value is fixed.

17. A computer graphics system as defined in claim 15 in which the value is a predetermined function of a variable.

18. A computer graphics system as defined in claim 17 in which the variable is time, thereby providing for animation of the instantiated phenomenon.

19. A computer graphics system as defined in claim 15 in which the value is provided by a property control tree, comprising at least one node defining a function.

20. A computer graphics system as defined in claim 19 in which the value is fixed.

21. A computer graphics system as defined in claim 19 in which the value is a predetermined function of a variable.

22. A computer graphics system as defined in claim 21 in which the variable is time, thereby providing for animation of the instantiated phenomenon.

23. A computer graphics system as defined in claim 19 in which at least one function defines a motion curve.

24. A computer graphics system as defined in claim 19 in which at least one function defines a texture look-up function.

25. A computer graphics method of generating an image of a scene from a representation to which at least one instantiated phenomenon has been attached, said instantiated phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics method comprising:

A. a pre-processing step of determining whether the at least one instantiated phenomenon requires a pre-processing operation in connection with said representation, and, if so, performing said pre-processing operation to generate a pre-processed representation of the scene; and

B. a rendering step of generating a rendered image from said pre-processed representation of the scene.

26. A computer graphics method of generating an image of a scene from a representation to which at least one instantiated phenomenon has been attached, said instantiated phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics method comprising:

A. a rendering step of generating a rendered image from said representation of the scene; and

B. a post-processing step of determining whether the at least one instantiated phenomenon requires a post-processing operation in connection with said representation and, if so, performing said post-processing operation.

27. computer graphics method of enabling an operator to create a phenomenon, the phenomenon comprising an encapsulated shader DAG comprising at least one shader node, the computer graphics method comprising:

A. providing base shader node database configured to store a plurality of base shader nodes, each base shader node including a shader;

B. a phenomenon creator step of enabling said operator to interconnect said base shader nodes from said base shader node database into a DAG, and of verifying that interconnections among said base shader nodes as provided by said operator comprise a DAG.

28. A computer graphics method of enabling an operator to generate, from a phenomenon, an instantiated phenomenon, the phenomenon comprising an encapsulated shader DAG comprising at least one shader DAG including at least one shader node, the computer graphics method comprising:

A. providing a phenomenon database configured to store said phenomenon, and

B. a phenomenon editor step of enabling said operator to select said phenomenon and provide a value for at least one parameter associated with said at least one shader node.