1. STEP and Scriptable CAx Tool Integration
Doug Cheney
Senior Software Engineer
International TechneGroup Incorporated

2. Complimentary Interoperability Approaches
Data integration : Exchange product data via a STEP model representation
Complete, standalone definition of model
Requires two model conversions: native to standard to target
Native model is duplicated in standard and target system formats
Systems integration : Share product data via CADScript--a neutral application programming interface
Only data and behavior needed by applications
Requires access to licensed installations of CAD systems
Native model stays in native system
Native
Model
Neutral
Target
System
Systems
Engineer
Component
Local
System
Model
CADScript
Remote

3. Multi-CAD data and algorithm access
CADScript Overview
Multi-CAD data and algorithm access
with scripting ease
IGES & STEP
and platform independence
Pro/ENGINEER
CATIA
I-DEAS
UG and Parasolid

4. Complimentary Usage Scenarios
Data integration using STEP
Multi-disciplinary repository of all product data
Long-term data retention
Legacy data migration
Systems integration using CADScript
Multi-CAD application
Collaborative engineering
Cross-platform application
Multi-system assembly design

5. Multi-CAD Application Example
Application Domain
CAD Model Quality Control
Key CAD Interface Requirements
Support for each of the major CAD applications (e.g., CATIA, I-DEAS, Pro/E and UG) and formats (IGES, STEP, Parasolid)
Access to native CAD data and algorithms (no data exchange)
Identical diagnostic algorithms for all systems
Focus on diagnostic development, not system integrations
Application Integration Success Metrics
CADScript V2.0 – 130K lines of C++ CADScript V3.0 – 29K lines of Python
CADScript V3.0 – 19 Diagnostics CADScript V4.0 – 40 Diagnostics

6. Multi-CAD Application Architecture
Menu
Callbacks
Application
Algorithms
Application
User Interface
CADScript
Customer Software UG
Pro/E
CATIA
ITI Software
I-DEAS
PDE/Lib
CAD Vendor Software

7. Collaborative Engineering Example
Application Domain
CAD Model View and Mark-up
Key CAD Interface Requirements
Support for each of the major CAD systems (CATIA, I-DEAS, Pro/E and UG)
Model query using precise measurements (i.e., no translation)
Assembly based queries
Web based client/server architecture
High performance and large scalability
Application Integration Success Metrics
Very short time-to-market for “production-ready” (multi-CAD) visualization product (less than 6 months)

8. Collaborative Engineering Architecture
Client
Server
class PartSession:
def demo(self)
def demoStep2(self, partFile, tesTol, edgeTol)
def display(self)
def area(self, uniqId)
def length(self, uniqId)
def modifyParameter(self, uniqId, rhs, type) …
Application Server
CADServer
HTTP (URL)
requests
URL Call Mapper
Web Browser
Calls
Java
Applet
CADScript
Customer Software
The web browser demonstration uses a simple HTML based interface to allow viewing and modification of parameters in a model located on the server. The server session code is defined in a class called “PartSession”. When a URL is accessed by the web browser, a method in the PartSession class is invoked that generates and returns HTML to the browser. This HTML contains additional links (that map to methods in PartSession) as well as some JavaScript code and a reference to a small Java applet that allows 3D visualization and interaction. When loaded, the viewer requests a tessellated representation of the model from the server. The viewer can be put into a mode that allows the user to select edges or faces. When an entity is selected, a server side method is called to compute the length or area of the entity (the computation is done in the CAD system via CADScript). An additional HTML page allows the user to view and modify parameters in the model. After making changes, the model can be regenerated by a button in the viewer.
ITI Software UG
Pro/E
CATIA
CAD Vendor Software
I-DEAS
PDE/Lib
Example browser request:

9. Cross-Platform Application Example
Application Domain
Coordinate Measuring Machine (CMM)
Key CAD Interface Requirements
Access UNIX-only CAD (CATIA V4) data from an NT client
The application requests a tessellated version of the CAD model from the server, the precise CAD geometry/topology is never sent to the client
Application Integration Success Metrics
Realization of NT-only solution with access to UNIX data

10. Cross-Platform Application Architecture
NT Client
UNIX Server
Application Client
class CadModel:
def displayPart()
def gridFace()
def projectPoints() …
Menu
Callbacks
Application Server
class ApplSession:
def displayPart()
def gridFace()
def projectPoints() …
HTTP (URL)
requests
CADServer
URL Call Mapper
CMM
Application
C++ Proxy Layer
(automatically generated from PartSession.py)
CADScript
Customer Software
ITI Software UG
Pro/E
CATIA
CAD Vendor Software
I-DEAS
PDE/Lib

11. Multi-CAD Assembly Design Example
Application Domain
Parametric Assembly Design
Key CAD Interface Requirements
Dynamic access to the latest version of component models in any supported CAD system (CATIA, I-DEAS, Pro/E and UG)
Interact with all components within a single CAD system user interface
Model query using precise measurements (i.e., no translation)
Parametric modification of remote components driven by local parameters
Application Integration Success Metrics
Enabling true multi-CAD assembly design!

12. Multi-CAD Assembly Design Architecture
Client
Server
Application Client
class PartClient:
def cmdAddExtPart()
def cmdExtPartMass() …
Menu
Callbacks
Application Server
class PartSession:
def openModel()
def parameters()
def modifyParameter() …
HTTP (URL)
requests
CADServer
URL Call Mapper
Unigraphics
Python Proxy Layer
(automatically generated from PartSession.py)
CADScript
The embedded client consists of a CADScript program running within the UG environment. The key class in the program is called “PartClient”. During construction, PartClient registers several menu callbacks so that picking items in the new FIPER menu results in a PartClient method being invoked.
PartClient communicates with the same server as the web browser demonstration used. However, instead of requesting URLs, it uses a proxy layer that was automatically generated from the PartSession.py file. The proxy layer contains a class that mirrors the PartSession class and its methods on the client side. This allows the client code to interact with PartSession methods as if they were all local rather than running on another system.
The PartClient class maintains several data structures to allow “external parts” to be instantiated within the UG environment. Although these parts look like UG geometry, they are actually UG user defined objects with graphics that are obtained from the server. The FIPER menu adds a number of commands for interacting with these parts.
Almost all the code in PartClient is independent of the CAD system it is running in. The only UG/Open calls made are for creation of UDOs to represent the external parts.
CADScript
Customer Software
ITI Software UG
Pro/E
CATIA
CAD Vendor Software
I-DEAS
PDE/Lib

13. Summary
System integration is a complimentary approach to data integration using STEP
System integration empowers dynamic usage scenarios
Instant access to the latest versions of native CAD models
Precise measurements performed by native CAD systems
Consistent parametric modifications across CAD systems
Flexible software architecture enabling remote CAD system control via URL calls
Rapid application development without software integration nightmares (no build problems)
Simple, concise, and intuitive application logic
Multi-CAD assembly design example: client is only 570 lines of Python code, server is only 551 lines