 Method and apparatus for geometric model deformation using wires |
| It is an object of the present invention to provide a modeling primitive based on a wire. It is ... |
|
| Object movement simulation apparatus |
| In view of the foregoing, it is therefore an object of the present invention to provide an object ... |
|
| Weather simulation system |
| One aspect of the invention is a method of using a computer to generate a visual display of weather ... |
|
| Efficient rendering utilizing user defined shields and windows |
| The above-stated problems and related problems of the prior art are solved with the principles of ... |
|
| Meshing method and apparatus |
| In view of the foregoing and other problems and drawbacks of the conventional systems and methods, ... |
|
| Interactive authoring of 3D scenes and movies |
| The computer system illustrated in FIG. 1--which includes mouse 37, keyboard 35, CPU 31 and CRT 33-... |
|
| System for polygon interpolation using instantaneous values in a variable |
| At present, perhaps video games are the most commonly known form of computer graphics apparatus. H... |
|
| Computer graphics system and method for texture mapping using triangular interpolation |
| OF THE PREFERRED EMBODIMENTS The present invention is directed to a computer graphics system and ... |
|
| Determining texture coordinates in computer graphics |
| I claim: 1. A method for obtaining a texture coordinate TC1 of a point Q' to be displayed by a ... |
|
| SDRAM data allocation system and method utilizing dual bank storage and retrieval |
| In one embodiment of the invention, a method is provided for allocating data among first and second ... |
|
|
Method and apparatus for shading graphical images in a data processing system
| Details |
Inventors: Tannenbaum, David Conrad; Bowen, Andrew David; Horton, Robert Spencer;
Assignee: International Business Machines Corporation (Armonk, NY)
Primary Examiner: Powell; Mark R.
Assistant Examiner: Huynh; Ba
Attorney, Agent or Firm: Walker; Mark S., Bumgardner; Barry J., Dillon; Andrew J.
The present invention provides an apparatus for displaying an image of an object, as illuminated by a light source, on a display within a computer graphics display system. The image is graphically represented by a mesh of polygons and each polygon within the mesh has a surface defined by a set of vertices. The vertices define the surface of the polygon. The apparatus includes a processor, such as a rasterizer, that is responsive to each set of vertices for rendering each surface within the mesh of polygons in response to ambient lighting to produce a number of initially rendered surfaces within the mesh of polygons. Phong shading is utilized by the present invention. The processor produces a specular highlight contribution for each surface within the mesh of polygons utilizing a halfway vector, pointing from each surface to a direction halfway between a light vector and a vector pointing towards a viewpoint, associated with a vector normal to each surface. Diffuse color contributions are generated within the processor using a light vector from a surface pointing to an illumination source associated with a vector normal to each surface. The specular highlight contribution and the diffuse color contribution for each surface of the initially rendered surfaces are summed to produce finally rendered surfaces within the mesh of polygons. These finally rendered polygons are used to display the image within the computer graphics display system. |
|
DETAILED DESCRIPTION It is therefore one objective of the present invention to provide a method and apparatus for producing a graphical image.
It is another objective of the present invention to provide a method and apparatus for shading a graphical image displayed within a data processing system.
It is yet another objective of the present invention to provide a method and apparatus for shading polygons displayed in a data processing system minimizing undesirable artifacts.
The foregoing objectives are achieved as is now described.
The present invention provides an apparatus for displaying an image of an object, as illuminated by one or more light sources, on a display within a computer graphics display system.
The image is graphically represented by a mesh of polygons and each polygon within the mesh has a surface defined by a set of vertices.
The vertices define the surface of the polygon.
The apparatus includes a processor, such as a rasterizer, that is responsive to each set of vertices for rendering each surface within the mesh of polygons in response to ambient lighting to produce a number of initially rendered surfaces within the mesh of polygons.
The processor also produces a specular highlight contribution for each surface within the mesh of polygons utilizing a halfway vector, pointing from each surface to a direction halfway between a light vector and a vector pointing towards a viewpoint, associated with a vector normal to each surface.
Diffuse color contributions are generated within the processor using a light vector from the surface pointing to an illumination source associated with a vector normal to the surface.
The specular highlight contribution and the diffuse color contribution for each surface of the initially rendered surfaces are summed to produce finally rendered surfaces within the mesh of polygons.
These finally rendered polygons are used to display the image within the computer graphics display system.
The above as well as additional objects, features, and advantages of the present invention will become apparent in the following detailed written description
|
| Related patents |
|
|
Method for a neural network for representing imaging functions
It is an object of the invention to provide a method of representing a neuronal network of the abovementioned type, this method establishing an imaging in a rapid and ...
|
|
|
Substrate for ink-jet head, having an optical element ink-jet head, and ink-jet apparatus
An ink-jet head which solves the above-mentioned problems, comprises: a discharge port for discharging an ink, and an ink channel which communicates with the discharge ...
|
|
|
Column redundancy for two port random access memory
It is an object of the invention to provide a two port random access memory with a matrix array and redundant columns, to store data bits at predetermined logical column ...
|
|
|
Dynamic semiconductor memory device with high-speed serial-accessing column decoder
It is therefore an object of the present invention to provide a new and improved technique for high-speed serial-accessing operation in MOS memory devices. It is another ...
|
|
|
Multi-channel token ring
In view of the shortcomings of the prior art, it is a primary object of this invention to provide interconnected workstations and other devices with optimal use of multi-...
|
|
|
Semiconductor memory device and method of data transfer therefor
The present invention was made to solve the above described problem and its object is to prevent damage to the data stored in a non selected memory cell when partial ...
|
|
|
Virtual access cache protection bits handling method and apparatus
FIG. 1 illustrates a block level diagram of a portion of a computer system incorporating the present invention. The computer system of FIG. 1, includes a virtual ...
|
|
|
Programmable VESA unified memory architecture (VUMA) row address strobe (RAS)
One advantage of the present invention is that it requires only a minimum amount of hardware modification to core logic (e.g., the memory controller device). Another ...
|
|
|
Multi-port RAM having functionally identical ports
What is claimed is: 1. A multi-port memory device comprising on a single chip: first and second input/output pins for providing data input and output, a DRAM main memory ...
|
|
|
Image processor and method for processing pixel data
In accordance with the invention there is provided an image processor for processing pixel data defining an image and comprising image processing logic for detecting ...
|
|
|
CPUs 
