Cloud Frontiers: A Deep Dive into Serverless Spatial Data and FME
Preserving Computer-Aided Design, Digital Preservation Coalition Report
1. because good research needs good data
Preserving Computer-Aided Design
Digital Preservation Coalition Report
Alex Ball
DCC/UKOLN, University of Bath
21 October 2013
Glasgow University
Except where otherwise stated, this work is licensed
under Creative Commons Attribution 2.5 Scotland: http:
//creativecommons.org/licenses/by/2.5/scotland/
DEDICATE Final Seminar
21 October 2013
Supported by
3. DPC Technology Watch Report
Preserving
Computer-Aided
Design (CAD)
Alex Ball
http://dx.doi.org/10.7207/twr13-02
DPC Technology Watch Report 13-02 April 2013
DEDICATE Final Seminar
21 October 2013
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4. Outline
Curation challenges for CAD
The CAD format problem
The rationale problem
The contextual problem
Final thoughts
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21 October 2013
6. Lasting value of CAD
c Field Archaeology Specialists
c Alexander C. Schreyer
Public domain
DEDICATE Final Seminar
c Worcestershire Archaeological Service
21 October 2013
7. Nature of CAD systems
…
Typical CAD system: new version every 6 months, end-of-life
after 10 years.
…
Dependence on particular modelling kernel
Intense competition between vendors for customers
…
…
…
…
Innovation: new features being added
Need to retire old systems ! time-limited licences
Fear of losing customers to rival systems ! lock-in
DEDICATE Final Seminar
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8. Integration with other systems
Finite
Element
Analysis
System
Geographic
Information
System
CAM
System
CAD
System
Animation
System
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...
High
Quality
Renderer
21 October 2013
9. Relationship with other documents
Bill of
Materials
Process
Model
CAD
Model
Rationale
Model
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Archaeology
Database
...
Systems
Models
21 October 2013
10. The CAD format problem
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11. Software emulation
Pros
…
CAD model unchanged
Cons
…
Licence may not allow it
…
Need to preserve expertise in the system
…
Hard to maintain integration with newer systems
DEDICATE Final Seminar
21 October 2013
12. Rolling format migrations
Pros
…
Models stay usable by current designers and systems
Cons
…
Incremental data loss/corruption
…
Each migration needs to be validated, problems resolved
…
Migration path may run out . . .
DEDICATE Final Seminar
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13. Normalisation
Pros
…
Limited data loss
…
Support for archival format likely to improve rather than
degrade over time
Cons
…
Some data loss/corruption
…
Migration needs to be validated, problems resolved
DEDICATE Final Seminar
21 October 2013
14. Normalisation: full exchange formats
DXF: DWG Exchange Format
…
Not enough documentation?
STEP: ISO 10303
… Too much documentation? Key parts:
…
…
…
…
Part 21: Clear text encoding of the exchange structure (‘STEP
file’)
AP 203: Configuration controlled 3D designs of mechanical parts
and assemblies
AP 214: Core data for automotive mechanical design processes
AP 242: Managed model-based 3D engineering
…
CAx Implementer Forum
…
Basis for other standards, e.g. IFC, LOTAR
DEDICATE Final Seminar
21 October 2013
15. Normalisation: visualisation formats
Standards
U3D Universal 3D – ECMA-363
X3D ISO/IEC 19775, 19776, 19777
IGES Initial Graphics Exchange Specification – ANSI
Y14.26M-1981 . . . ANS US/PRO/IPO-100-1996
PRC Product Representation Compact – ISO/PRF 14739
JT ISO 14306
Non-standards
DWF/DWFx AutoCAD DWG Web Format
3D XML CATIA visualisation format
DEDICATE Final Seminar
21 October 2013
16. FACADE recommendations
CAD models should be stored in
1. the original format
2. a full exchange format, e.g. STEP
3. a desiccated format, e.g. IGES
4. an access format, e.g. 3D PDF
DEDICATE Final Seminar
21 October 2013
17. Validation
Example from
LOTAR International
1. Generate point
cloud in original
software
2. Export to
normalisation
format
3. Import into new
software
4. Overlay point
cloud: do the
points still lie on
surfaces/edges?
c ITI/SNECMA
DEDICATE Final Seminar
21 October 2013
18. Lightweight models with multilayer annotations
Unclassified
annotations for
manufacture
Classified
annotations for
designers
Geometry layer
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21 October 2013
21. Construction history modelling
1. Insert cylinder l = 20 r = 1.0
Change cylinder l = 40 r = 0.5
2. Insert sprocket r = 3.0
3. Fit sprocket to cylinder
4. Group cylinder and sprocket
5. Scale group by 1.75⇥
...
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21 October 2013
22. Automated information capture
Non-intrusive engineering
knowledge acquisition
User logging
Knowledge
store
Design/
plan
Data
analysis
Knowledge
capture/
formalization
c Raymond Sung/
Heriot-Watt University
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21 October 2013
23. Design Rationale Editor
c Rob Bracewell/University of Cambridge
DEDICATE Final Seminar
21 October 2013
26. Key ERIM Research Findings
1. Poor framework for
…
…
…
pre-project considerations of data management;
data management during the research;
during-project data management for post-project re-use.
2. Poor knowledge of context in which data were generated:
…
…
…
engineering research data is very diverse;
large number of diverse research data records;
relations between data records complex.
3. Knowing the context is vital for understanding data.
Slide: Mansur Darlington
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21 October 2013
27. Collecting metadata
Minimum Mandatory Metadata Set; REDm-MED version at:
http://opus.bath.ac.uk/30372/
…
Drew on PREMIS for preservation metadata
…
Drew on DataCite for descriptive metadata
…
Excluded metadata that could easily be generated later
…
We looked for ways to collect it automatically
(NB: an extensive specification of what metadata to collect for
archaeological CAD can be found at:
http://guides.archaeologydataservice.ac.uk/g2gp/Cad_Toc)
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30. Recommendations
…
Establish why a CAD model will be kept, then target the
required properties for preservation.
…
Create tests that can prove whether these properties have
survived.
…
Keep native CAD models for as long as they can be read.
…
Normalise to STEP and a visualisation standard (or two).
…
Don’t forget supporting documentation, especially local
conventions, ‘house style’, specifications, rationale records . . .
…
Campaign for better support for standard formats in CAD
systems!
DEDICATE Final Seminar
21 October 2013
31. because good research needs good data
Thank you for your attention
DCC Website: http://www.dcc.ac.uk/
Alex Ball: http://alexball.me.uk/
Preserving CAD DPC Technology Watch Report:
http://dx.doi.org/10.7207/twr13-02
DEDICATE Final Seminar
21 October 2013