WO2006105505A2

WO2006105505A2 - System and method to determine a visibility solution of a model

Info

Publication number: WO2006105505A2
Application number: PCT/US2006/012377
Authority: WO
Inventors: Timothy R. Anderson; Ronald T. Conerly; Aditya Gurushankar; Daniel C. Staples; Mallikarjuna Gandikota; Prasad Pringali
Original assignee: Siemens Product Lifecycle Management Software Inc; UGS Corp
Current assignee: Siemens Industry Software Inc
Priority date: 2005-03-31
Filing date: 2006-03-31
Publication date: 2006-10-05
Anticipated expiration: 2007-09-30
Also published as: US20060250421A1; EP1864257A2; WO2006105505A3

Abstract

A system, method, and computer program for determining a visibility solution of a model comprising the steps of rendering a model having a plurality of parts with at least one color value encoded for an at least one corresponding surface identity; distinguishing a plurality of exterior parts from a plurality of interior parts based on said at least one corresponding surface identity; and identifying a plurality of features in said model not copied into a composite image and appropriate means and computer-readable instructions.

Description

SYSTEM AND METHOD TO DETERMINE A VISIBILITY SOLUTION OF A MODEL

Priority of Application

[Para 1 ] The present application claims priority of U.S. Provisional

Application Serial No. 60/666,973 filed March 31, 2005, which is incorporated

herein by reference.

Technical Field

[Para 2] This invention relates generally to computer graphics. More

specifically, the invention relates to a system and method of determining a

visibility solution of a CAD assembly.

Background

[Para 3] The computer has greatly affected essentially all forms of

information management, including computer aided design and drafting (CAD)

tools. Some simpler geometric modeling computer program products can only

model in two dimensions at a time, while more complex and powerful computer

program products provide three dimensional editing and visualization capabilities.

[Para 4] Three dimensional geometric modeling programs can generate a

complex high-level assembly that can comprise one or more constituent 3D solid

shapes. For example, a table assembly could comprise a solid shape for each leg

of the table, where each leg is an identical design placed relative to each other,

as well as a solid shape for a flat table top. Today, however, CAD

representations are becoming more and more complex; typically combining

numerous intricate 3D drawings to create a final product like an airplane, a car

or even a factory. Each level of abstraction requires various degree of

granularity, particularly when it comes to comparing manufacturing versus bill of

material information versus conceptual design. Likewise, when rendering a 3D

model in its entirety, a computer requires considerable resources from its central

processing unit (CPU) and/or random access memory (RAM), for example. In

the industry, it is common to spend hours to days of computing time to render a

highly complex structure.

[Para 5] The increased rendering time places a burden on computer

systems and organizations that desire rapid progression from design to

development. Therefore, when designing the 3D model of the high-level

structure, manufacturing entities have a need to reduce rendering times of each of the individual sub-assemblies that comprise the higher-level assembly while

maintaining the design integrity of the entire design concept.

[Para 6] Furthermore, users of CAD systems require various levels of

product structure where at one end there is a need for detailed design

information, and at the other end, a simplified representation is needed. That

being said, those users have to easily switch between simplified and design

representations throughout the product design process, while maintaining

constant product definition. Those same users want to balance the ability to

freely deliver to third parties a simplified representation of 3D models that does

not divulge potential intellectual property with sufficient detail to communicate

the product design.

[Para 7] There is a need for a solution that can efficiently and effectively

simplify the 3D representation of a designed product particularly at various levels

of design when various needs for detailed information is required. There is also

a need for a solution that can provide the ability for a user to deliver some level

of product detail to prospective customers and clients without unintentionally

divulging proprietary information.

Summary

[Para 8] To achieve the foregoing, and in accordance with the purpose of

the presently preferred embodiment as broadly described herein, the present

invention provides a method to determine a visibility solution of a model

comprising the steps of rendering a model having a plurality of parts with at

least one color value encoded for an at least one corresponding surface identity;

distinguishing a plurality of exterior parts from a plurality of interior parts based

on said at least one corresponding surface identity; and identifying a plurality of

features in said model not copied into a composite image. The method, further

comprising the step of displaying said plurality of parts from at least one

orientation. The method, further comprising the step of displaying said

composite image comprised of said exterior parts and lacking said plurality of

features. The method, further comprising the step of preparing said model to

improve accuracy of a rendering operation. The method, further comprising the

step of implementing at least one filtering algorithm to adjust a quality of

analysis of said rendering. The method, further comprising the step of preparing

said model to adjust accuracy of a rendering operation wherein said accuracy is

adjusted by tessellating said model. The method, wherein said step of rendering

operates to depict said model as a tessellated version of a geometrical

representation of a plurality of surfaces.

[Para 9] Another advantage of the presently preferred embodiment is to

provide a computer-program product tangibly embodied in a machine readable

medium to perform a method to determine a visibility solution of a model,

comprising instructions for rendering a model having a plurality of parts with at least one color value encoded for an at least one corresponding surface identity;

instructions for distinguishing a plurality of exterior parts from a plurality of

interior parts based on said at least one corresponding surface identity; and

instructions for identifying a plurality of features in said model not copied into a

composite image. The computer-program product, further comprising the

instructions for displaying said plurality of parts from at least one orientation.

The computer-program product, further comprising the instructions for displaying

said composite image comprised of said exterior parts and lacking said plurality

of features. The computer-program product, further comprising the instructions

for preparing said model to improve accuracy of a rendering operation. The

computer-program product, further comprising the instructions for implementing

at least one filtering algorithm to adjust a quality of analysis of said rendering.

The computer-program product, further comprising the instructions for preparing

said model to adjust accuracy of a rendering operation wherein said accuracy is

adjusted by tessellating said model. The computer-program product, wherein

said instructions for rendering operates to depict said model as a tessellated

version of a geometrical representation of a plurality of surfaces.

[Para 10] Another advantage of the presently preferred embodiment is a

data processing system having at least a processor and accessible memory to

implement a method to determine a visibility solution of a model, comprising

means for rendering a model having a plurality of parts with at least one color

value encoded for an at least one corresponding surface identity; means for

on said at least one corresponding surface identity; and means for identifying a plurality of features in said model not copied into a composite image.

[Para 1 1 ] Still another advantage of the presently preferred embodiment is a

computer-program product for determining a visibility solution of a model, the

solution comprising a rendering operation on a model, wherein said rendering

operation encodes a plurality of parts with at least one color value to at least one

corresponding surface identity; a plurality of exterior parts distinguished from a

plurality of interior parts based on said at least one corresponding surface

identity; whereby said model displays a composite image of said exterior parts.

[Para 1 2] And yet another advantage of the presently preferred embodiment

is a computer-program product for determining a visibility solution of a model,

the product comprising a rendering operation that receives a prepared model,

wherein said preparation adjusts accuracy of said rendering operation; at least

one filtering algorithm to adjust a quality of analysis following said rendering

operation; whereby said model is a tessellated version of a geometric

representation of a plurality of surfaces.

[Para 1 3] A further advantage of the presently preferred embodiment is a

visibility solution of a model embodied on a computer-readable medium on a

computer in conjunction with a application, the visibility solution comprising a

reduced form of said model derived from a designed form of said model, having

a plurality of exterior faces, wherein said exterior faces consist of a plurality of

components from said design form.

[Para 14] And a further advantage of the presently preferred embodiment is

a method to determine a visibility solution of a model comprising the steps of

implementing at least one filtering algorithm to adjust a quality of analysis of said rendering; preparing said model to adjust accuracy of a rendering operation

wherein said accuracy is adjusted by tessellating said model; rendering a model

having a plurality of parts with at least one color value encoded for an at least

one corresponding surface identity, operating to depict said model as a

tessellated version of a geometrical representation of a plurality of surfaces;

on said at least one corresponding surface identity; identifying a plurality of

features in said model not copied into a composite image; displaying said

plurality of parts from at least one orientation; and displaying said composite

image comprised of said exterior parts and lacking said plurality of features.

[Para 1 5] Other advantages of the presently preferred embodiment will be

set forth in part in the description and in the drawings that follow, and, in part

will be learned by practice of the invention.

[Para 16] The presently preferred embodiment will now be described with

reference made to the following Figures that form a part hereof. It is

understood that other embodiments may be utilized and changes may be made

without departing from the scope of the present invention.

Brief Description of the Drawings

[Para 1 7] A presently preferred embodiment will hereinafter be described in

conjunction with the appended drawings, wherein like designations denote like

elements, and:

[Para 18] FIG. 1 is a block diagram of a computer environment in which the

presently preferred embodiment may be practiced;

[Para 1 9] FIG. 2 is a logic flow diagram for a visibility solution in the

presently preferred embodiment;

[Para 20] FIG. 3 is an illustration of a detailed logic flow diagram of the

visibility solution in the presently preferred embodiment;

[Para 21 ] FIG. 4 is a 3D housing in an axonometric orientation;

[Para 22] FIG. 5 is an illustration of an orthogonal plane view of a shaft

extended through a hole;

[Para 23] FIG. 6 is a design representation of a 3D assembly model in

axonometric orientation;

[Para 24] FIG. 7 is a 3D assembly model in axonometric orientation in one

solid color with each part initially identified as interior;

[Para 25] FIG. 8 is an illustration of an orthogonal orientation of the gear

reducer assembly;

[Para 26] FIG. 8 is an illustration of a partial view of a gear reducer

assembly;

[Para 27] FIG. 9 is an illustration of a close-up view of a bolt, showing

exterior faces as white, and an interior face as magenta;

[Para 28] FIG. 10 is an illustration of an axonometric orientation of the gear reducer assembly in simplified representation; and

[Para 29] FIG. 11 is an illustration of a close-up view of a gear reducer

assembly following a visibility solution where a hole and a plurality of bolts are

missing from a design representation.

Detailed Description of the Preferred Embodiments

[Para 30] The numerous innovative teachings of the present application will

be described with particular reference to the presently preferred embodiments.

It should be understood, however, that this class of embodiments provides only

a few examples of the many advantageous uses of the innovative teachings

herein. The presently preferred embodiment provides, among other things, a

system and method to determine a visibility solution of a computer aided design

(CAD) assembly. Now therefore, in accordance with the presently preferred

embodiment, an operating system executes on a computer, such as a general-

purpose personal computer. Figure 1 and the following discussion are intended

to provide a brief, general description of a suitable computing environment in

which the presently preferred embodiment may be implemented. Although not

required, the presently preferred embodiment will be described in the general

context of computer-executable instructions, such as program modules, being

executed by a personal computer. Generally program modules include routines,

programs, objects, components, data structures, etc., that perform particular

tasks or implementation particular abstract data types, and the presently

preferred embodiment may be performed in any of a variety of known computing

environments.

[Para 31 ] With reference to Figure 1, an exemplary system for implementing

the presently preferred embodiment includes a general-purpose computing

device in the form of a computer 100, such as a desktop or laptop computer,

including a plurality of related peripheral devices (not depicted). The computer

100 includes a microprocessor 105 and a bus 110 employed to connect and enable communication between the microprocessor 105 and a plurality of

components of the computer 100 in accordance with known techniques. The

bus 110 may be any of several types of bus structures including a memory bus

or memory controller, a peripheral bus, and a local bus using any of a variety of

bus architectures. The computer 100 typically includes a user interface adapter

115, which connects the microprocessor 105 via the bus 110 to one or more

interface devices, such as a keyboard 120, mouse 125, and/or other interface

devices 130, which can be any user interface device, such as a touch sensitive

screen, digitized pen entry pad, etc. The bus 110 also connects a display device

135, such as an LCD screen or monitor, to the microprocessor 105 via a display

adapter 140. The bus 110 also connects the microprocessor 105 to a memory

145, which can include ROM, RAM, etc.

[Para 32] The computer 100 further includes a drive interface 150 that

couples at least one storage device 155 and/or at least one optical drive 160 to

the bus. The storage device 155 can include a hard disk drive, not shown, for

reading and writing to a disk, a magnetic disk drive, not shown, for reading from

or writing to a removable magnetic disk drive. Likewise the optical drive 160

can include an optical disk drive, not shown, for reading from or writing to a

removable optical disk such as a CD ROM or other optical media. The

aforementioned drives and associated computer-readable media provide non¬

volatile storage of computer readable instructions, data structures, program

modules, and other data for the computer 100.

[Para 33] The computer 100 can communicate via a communications channel

165 with other computers or networks of computers. The computer 100 may be associated with such other computers in a local area network (LAN) or a wide

area network (WAN), or it can be a client in a client/server arrangement with

another computer, etc. Furthermore, the presently preferred embodiment may

also be practiced in distributed computing environments where tasks are

performed by remote processing devices that are linked through a

communications network. In a distributed computing environment, program

modules may be located in both local and remote memory storage devices. All

of these configurations, as well as the appropriate communications hardware and

software, are known in the art.

[Para 34] Software programming code that embodies the presently preferred

embodiment is typically stored in the memory 145 of the computer 100. In the

client/server arrangement, such software programming code may be stored with

memory associated with a server. The software programming code may also be

embodied on any of a variety of non-volatile data storage device, such as a hard-

drive, a diskette or a CD-ROM. The code may be distributed on such media, or

may be distributed to users from the memory of one computer system over a

network of some type to other computer systems for use by users of such other

systems. The techniques and methods for embodying software program code on

physical media and/or distributing software code via networks are well known

and will not be further discussed herein.

[Para 35] Figure 2 is a logic flow diagram for a visibility solution in the

presently preferred embodiment. The present application describes an

innovative visibility solution practiced on a 3D CAD software application such as

SolidEdge® by UGS Corp, whereby a user, also referred to as a designer, displays a 3D assembly model that includes at least one part, component and/or

sub-assembly (Step 200). The 3D assembly model can be created natively on

the 3D CAD software application, or can be copied into the current application.

Likewise, the 3D assembly model can be designed and/or constructed by other

methods commonly known in the art of 3D assembly design.

[Para 36] Following the display of the 3D assembly model, next the 3D

assembly model is prepared for display to improve rendering accuracy, and if the

3D assembly model contains simplified geometry from a prior simplified

representation operation, then the simplified geometry is displayed along with

the other components of the 3D assembly model that have not been simplified

(Step 205). Simplified geometry is a generic term to identify any

part/component that has been simplified pursuant to the methods and teachings

disclosed herein. Likewise, components not shown in the design representation

view do not participate during the simplified representation mode in the creation

of the simplified representation.

[Para 37] Further to preparing the 3D assembly model for display, the display

color of the 3D assembly model is adjusted such that it is uniform throughout

and initially characterizes all faces to be simplified as interior. In the simplified

representation mode, the user can utilize the 3D software application to

show/hide parts, activate/inactivate parts, show parts as simplified/designed,

apply configurations, or change part styles using understood techniques. It is

understood that the term "parts" refers to any structural element of the 3D

assembly model, e.g., the face of a hex bolt is a "part" or the entire hex bolt

could be a "part" as identified by the user. [Para 38] Next, the user identifies which parts and/or components on the 3D

assembly model the presently preferred embodiment will ignore in the creation

of the simplified representation by using a graphic slider to ignore small parts

based on a slider value and if desirable can manually select parts to ignore. The

slider value can be adjusted to exclude a hole with a size of 0.05% of the area

containing the surface, for example. It is understood that the percentage size

could easily be more or less than 0.05%, depending on the design intent of the

user and that 0.05% is an arbitrary value shown for demonstrative purposes

only. Parts and components the designer identifies as "ignored" are not copied

into the resulting simplified assembly representation, and those same ignored

parts and components do not participate in a visibility solution to distinguish

exterior faces from interior faces. Likewise, "small" can be hard-coded into the

application disclosed such that the designer cannot modify the definition of small

as compared to the surface area of the assembly and/or component.

[Para 39] Further to the teachings discussed, the user is able to manipulate a

quality of analysis by selecting to render each surface of the 3D assembly model

as a finely tessellated depiction of a geometric representation of each surface.

The granularity of tessellation can vary from fine to coarse, where coarse

tessellation forms larger polygons such as triangles, squares or hexagons, while

fine tessellation forms smaller polygons. Tessellating and re-tessellating the 3D

assembly model varies the quality of the analysis by ignoring interior faces that

would otherwise be considered visible.

[Para 40] Once the 3D assembly model is prepared for display, the presently

preferred embodiment utilizes a visibility solution to continue the process of simplification (Step 210). Following the visibility solution, the resulting

composite image is returned for further processing and/or integration by the

same or different 3D CAD software application (Step 215).

[Para 41 ] Turning to Figure 3, a logic flow diagram of the visibility solution

disclosed in greater detail, where it accepts as input the prepared 3D assembly

model (Step 300). The disclosed preferred embodiment defaults to providing

24 orientations, where those orientations are orthogonal and/or axonometric

(Step 305). The designer can also define additional orientations by freely

rotating the 3D assembly model or using other means known in the 3D CAD

industry and commonly known by users of 3D design applications (Step 310).

The only limit to the number of desired orientations is the amount of time

needed to process the orientations and accumulate the results of the visibility

solution.

[Para 42] Next the visibility solution applies the orientation designated by the

designer (Step 315). At that time, the designer can use further known

techniques to manipulate the 3D assembly model to improve the quality of the

rendering, for example, optimizing zoom scale to increase model coverage,

optimizing depth buffer attributes, and adjusting orientation to decrease the

amount of viewed surface area. In selecting said orientation, the designer can

further adjust the quality of analysis by modifying the dimensions for the

rendering process. For example, a width and height can be reduced to improve

speed of the visibility solution but reduce the accuracy of the rendering.

[Para 43] Next, the resulting rendered image of the the 3D assembly model

displays information that is used to determine the identify of each visible surface of each occurrence of each component in the 3D assembly model, where the

displayed information is identified as one color for exterior processed surfaces

and another color for interior surfaces (Step 320). The presently preferred

embodiment employs the depth buffering feature of OpenGL to assign unique

colors to each of the rendered surfaces. OpenGL is an open source graphics

library that defines a cross-language cross-platform API for writing applications

that produce 3D and 2D computer graphics. Depth buffering is a technique to

determine which primitives in a model are occluded by other primitives such

that as each pixel in a primitive is rasterized, its distance from the eye-point

(depth value) is compared with the values stored in the depth buffer.

Accordingly, if the pixel's depth value is less than the stored value, the pixel's

depth value is written to the depth buffer, and its color is written to the color

buffer.

[Para 44] Put another way, the depth buffering works by associating a depth,

or distance, from the view plane with each pixel on the window so that the

distance from the view pane is computed. With depth buffering enabled, before

each pixel is drawn, a comparison is done with the depth value already stored at

the pixel. If the new pixel is closer than what's there, the new pixel's color and

depth values replace those that are currently written into the pixel. If the new

pixel's depth is greater than what's currently there, the new pixel is obscured,

and the color and depth information for the incoming pixel is discarded. In an

alternative embodiment, the depth buffering could occur via hardware instead of

the CAD software as disclosed. It is understood that any comparable graphics

library may be used, provided a feature similar to depth buffering is available. Likewise, a separate graphics library does not have to be used, but instead can

be integral into the CAD software. Following the depth buffering, the final

rendered image contains colored pixels that can be decoded and mapped back

from the surface rendered to that location in the 3D assembly model, as

orientated, with color values encoded with each surface as identified. This

results in the software application providing graphical feedback to the designer

by changing all processed faces identified as exterior of the various components

to a solid color.

[Para 45] The quality of the rendering thus far can be further scrutinized and

controlled by applying a plurality of filtering algorithms to the resulting image

that removes rendering artifacts common with various rendering techniques.

One such rendering artifact is called a speckle. The visibility solution can ignore

these speckle anomalies by applying a commonly used speckle removal tool

(Step 325). The speckle removal filter prevents speckles from affecting

surrounding areas in the rendered image, which decreases the number of

surfaces that comprise the final rendered image.

[Para 46] Following the application of filters to remove the rendering

artifacts, the visibility solution extracts the rasterized surfaces (Step 330) and

merges the resulting surfaces (Step 335) with a first visibility solution (Step

340). If the designer requires multiple orientations, then the visibility solution is

not complete (Step 345) and the visibility solution returns to selecting the next

orientation (Step 305) The 3D assembly model rendered from multiple

orientations and the results from each orientation are accumulated to represent

a composite visibility solution (Step 350) and whose result is returned for further processing and/or integration (Step 215)

[Para 47] Following the return for further processing, the designer has the

ability to identify insignificant components by rotating, zooming in/out, etc., to

inspect what the visibility solution identified as interior/exterior and re-run the

solution to select additional exterior faces from that specific orientation. One of

the benefits of the presently preferred embodiment is the components chosen to

be excluded, still participate in the visibility solution.

[Para 48] By way of example and not limitation, in Figure 4, a 3D housing in

axonometric orientation, the designer models a housing 400 having a shaft 405

extending outside the housing 400 through a hole 410 as further detailed in

Figure 5, an illustration of an orthogonal plane view of a shaft extended

through a hole. During coarse granularity tessellation, a plurality of gaps can

occur in the tessellated surfaces, e.g., the shaft 405 and the hole 410. The

presently preferred embodiment calculates through the gaps to find at least one

interior face 500 and identify the interior face 500 as exterior and/or visible.

The designer then notes the interior face 500, and excludes it from the

rendering.

[Para 49] The presently preferred embodiment is illustrated, by way of

example and not limitation, when the designer starts with Figure 6, an

axonometric orientation of a gear reducer assembly in design representation,

and determines to create a simplified representation of a gear reducer assembly

600 by initiating the presently preferred embodiment which causes the gear

reducer assembly to become one solid color with each part initially identified as

interior as illustrated in Figure 7, a 3D assembly model in axonometric orientation in one uniform color with each part initially identified as interior. In

an alternative embodiment, Figure 8 illustrates an orthogonal orientation of the

gear reducer assembly with unique colors assigned to the various visible surfaces

for each component.

[Para 50] Prior to initiating the visibility solution, the user determines to

ignore a small hole 900 and a plurality of small bolts 905 as illustrated in

Figure 9, a partial view of the gear reducer assembly, that will not be included

in the complete simplified representation. The presently preferred embodiment

allows the designer the ability to determine when to begin the visibility solution

by displaying a process button. While processing, the presently preferred

embodiment also provides the user the ability to cancel and review or modify the

visibility solution when appropriate.

[Para 51 ] Following the rendering (Step 320) the designer views a gear

reducer assembly, where Figure 10 is a close-up view of a bolt and shows the

exterior faces as white, and the interior faces as magenta, but illustrated in with

a diagonal-line. While the visibility solution resolved the exterior faces, it

calculates a bolt face 1000 as being interior, when in fact the bolt face 1000 is

exterior to the gear reducer assembly 600. Utilizing the 3D software application,

the designer then selects the bolt face 1000 as a member of the exterior faces

that comprise the gear reducer assembly 600 by use of a mouse click or other

known selection ability. Figure 11 illustrates an axonometric orientation of the

gear reducer assembly in simplified representation, the designer excluded the

small hole 900 and the small bolts 905 that are not present as seen at 1100 and

1105, respectively. [Para 52] The presently preferred embodiment may be implemented in digital

electronic circuitry, or in computer hardware, firmware, software, or in

combinations thereof. An apparatus of the presently preferred embodiment may

be implemented in a computer program product tangibly embodied in a

machine-readable storage device for execution by a programmable processor;

and method steps of the presently preferred embodiment may be performed by

a programmable processor executing a program of instructions to perform

functions of the presently preferred embodiment by operating on input data and

generating output.

[Para 53] The presently preferred embodiment may advantageously be

implemented in one or more computer programs that are executable on a

programmable system including at least one programmable processor coupled to

receive data and instructions from, and to transmit data and instructions to, a

data storage system, at least one input device, and at least one output device.

The application program may be implemented in a high-level procedural or

object-oriented programming language, or in assembly or machine language if

desired; and in any case, the language may be a compiled or interpreted

language.

[Para 54] Generally, a processor will receive instructions and data from a

read-only memory and/or a random access memory. Storage devices suitable for

tangibly embodying computer program instructions and data include all forms of

nonvolatile memory, including by way of example semiconductor memory

devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks

such as internal hard disks and removable disks; magneto-optical disks; and CD- ROM disks. Any of the foregoing may be supplemented by, or incorporated in,

specially-designed ASICs (application-specific integrated circuits).

[Para 55] A number of embodiments have been described. It will be

understood that various modifications may be made without departing from the

spirit and scope of the presently preferred embodiment, for example the

Direct3D library by Microsoft® could be used instead of the OpenGL library.

Likewise, following rendering, should poor silhouette edges occur, then those

edges can be further refined using various filtering schemes known in the art.

Therefore, other implementations are within the scope of the following claims.

Claims

We claim:

1. A method to determine a visibility solution of a model comprising the

steps of:

rendering a model having a plurality of parts with at least one color value

encoded for an at least one corresponding surface identity;

distinguishing a plurality of exterior parts from a plurality of interior parts

based on said at least one corresponding surface identity;

and

identifying a plurality of features in said model not copied into a

composite image.

2. The method of Claim 1, further comprising the step of displaying said

plurality of parts from at least one orientation.

3. The method of Claim 1, further comprising the step of displaying said

composite image comprised of said exterior parts and lacking said

plurality of features.

4. The method of Claim 1, further comprising the step of preparing said

model to improve accuracy of a rendering operation.

5. The method of Claim 1, further comprising the step of implementing at

least one filtering algorithm to adjust a quality of analysis of said

rendering.

6. The method of Claim 1, further comprising the step of preparing said

model to adjust accuracy of a rendering operation wherein said

accuracy is adjusted by tessellating said model.

7. The method of Claim 1, wherein said step of rendering operates to depict said model as a tessellated version of a geometrical representation

of a plurality of surfaces.

8. A computer-program product tangibly embodied in a machine readable

medium to perform a method to determine a visibility solution of a

model, comprising:

instructions for rendering a model having a plurality of parts with at least

one color value encoded for an at least one corresponding

surface identity;

instructions for distinguishing a plurality of exterior parts from a plurality

of interior parts based on said at least one corresponding

surface identity; and

instructions for identifying a plurality of features in said model not copied

into a composite image.

9. The computer-program product of Claim 8, further comprising the

instructions for displaying said plurality of parts from at least one

orientation.

10. The computer-program product of Claim 8, further comprising the

instructions for displaying said composite image comprised of said

exterior parts and lacking said plurality of features.

11. The computer-program product of Claim 8, further comprising the

instructions for preparing said model to improve accuracy of a

rendering operation.

12. The computer-program product of Claim 8, further comprising the

instructions for implementing at least one filtering algorithm to adjust a quality of analysis of said rendering.

13. The computer-program product of Claim 8, further comprising the

instructions for preparing said model to adjust accuracy of a

rendering operation wherein said accuracy is adjusted by

tessellating said model.

14. The computer-program product of Claim 8, wherein said instructions for

rendering operates to depict said model as a tessellated version of

a geometrical representation of a plurality of surfaces.

15. A data processing system having at least a processor and accessible

memory to implement a method to determine a visibility solution

of a model, comprising:

means for rendering a model having a plurality of parts with at least one

color value encoded for an at least one corresponding

surface identity;

means for distinguishing a plurality of exterior parts from a plurality of

interior parts based on said at least one corresponding

surface identity; and

means for identifying a plurality of features in said model not copied into

a composite image.

16. A computer-program product for determining a visibility solution of a

model, the solution comprising:

a rendering operation on a model, wherein said rendering operation

encodes a plurality of parts with at least one color value to

at least one corresponding surface identity; a plurality of exterior parts distinguished from a plurality of interior parts

based on said at least one corresponding surface identity;

whereby said model displays a composite image of said exterior parts.

17. A computer-program product for determining a visibility solution of a

model, the product comprising:

a rendering operation that receives a prepared model, wherein said

preparation adjusts accuracy of said rendering operation;

at least one filtering algorithm to adjust a quality of analysis following

said rendering operation;

whereby said model is a tessellated version of a geometric representation

of a plurality of surfaces.

18. A visibility solution of a model embodied on a computer-readable medium

on a computer in conjunction with a application, the visibility

solution comprising:

a reduced form of said model derived from a designed form of said

model, having a plurality of exterior faces, wherein said

exterior faces consist of a plurality of components from said

design form.

19. A method to determine a visibility solution of a model comprising the

steps of:

implementing at least one filtering algorithm to adjust a quality of

analysis of said rendering;

preparing said model to adjust accuracy of a rendering operation wherein

said accuracy is adjusted by tessellating said model; rendering a model having a plurality of parts with at least one color value

encoded for an at least one corresponding surface identity,

operating to depict said model as a tessellated version of a

geometrical representation of a plurality of surfaces;

distinguishing a plurality of exterior parts from a plurality of interior parts

based on said at least one corresponding surface identity;

identifying a plurality of features in said model not copied into a

composite image; and

displaying said composite image comprised of said exterior parts and

lacking said plurality of features.