1. CollabCAD® Reverse Engineering Solution
Mr. G. Prasad and Mr. S.Senthil Kumar
CAD Group, National Informatics Centre
Ministry of Communications and Information Technology
September 2005
Technology Appreciation Seminar, IIT, Chennai

2. AGENDA Welcome What is CollabCAD? Reverse Engineering
Q & A and Thank you

3. Welcome and Introduction
National Informatics Centre is a Government of India organization providing IT Solutions (
Built, Operates & Owns NICNET: Satellite based Computer Communication Network With Over 1200 Nodes
CAD Division is involved in CAD/CAD/CAE Software Development and Product development
Developing an indigenous 3D CAD/CAM software COLLABCAD
Expertise in Open-source software and Open standards (

4. AGENDA Welcome What is CollabCAD ®? Reverse Engineering
Q & A and Thank you

5. What is CollabCAD® ?
Indigenous Surface/Solid modeler based on Java, Java3D and Open Cascade and other Open-source solutions
Developed by CAD group of National Informatics Centre, New Delhi
Registered in US Patent Trademark office
First version available for download in 2001
Recent public release available at
Runs on Linux, Windows

6. CollabCAD®: Consortium and Development Cells
Bhabha Atomic Research Centre, Mumbai (CDC)
Vikram Sarabhai Space Centre, Trivandrum (CDC)
Aeronautical Development Agency, Bangalore
National Aerospace Laboratory, Bangalore
Structural Engineering Research Centre, Chennai
Defence Research and Development Laboratory, Hyderabad
Tata Technology Ltd., Pune
Gas Turbine Research Establishment, Bangalore
ISAC and LPSC, Bangalore

7. CollabCAD® : Logo and Splash Image
Logo and Product Name registered
Splash Image acknowledging Open-source systems like
Java, Java3D
Open Cascade
PtPlot, Cassowary
Zope, PostgreSql, Jython

8. CollabCAD® …… Why and What’s so special ?
Collaborative .. Intranet and Internet , also Standalone
Uses proven Open source software and Open standards
Cost-effective solution as development cost is low
Geometry Workbench using two way IGES and STEP standards
Client-side scripting using Jython for automation
XML based geometry data storage and Database connectivity
Multiple language HTML help and also context-based search
Plot Configurator, BOM and Barcode for ERP Solution
VRML Preview
Reverse Engineering, Slicing and Scaling of geometry

9. What is Reverse Engineering?
Tool for redesign, replication, analysis, or inspection of a physical object
3D Scanning Tools enable you to capture hundreds of thousands of points in a few seconds
Objects can be converted to 3D point cloud data
Scanner output provides data in a format that can be directly used in a surface/solid modeling system

10. What is Point Cloud Data ?
New Products are redesigns of older products
3D Digitized data defining a part or object
Obtained from measurement device like CMM and 3D laser scanners
Accurate definition of a part, thousands or millions of coordinate points are required
Rework of old designs and tools

11. What use this data in CollabCAD® ?
Data necessary for an engineer/designer from an existing component or object
Having the cloud point data of the component is the ‘starting point’ to reverse-engineer a manufacturability part
Input file formats supported are STL, 3D ASCII, IGES
Amount of data handling is limited by the amount of RAM , benchmarking runs have successfully loaded 5 lakh to 10 lakh points

12. Facet normal are also available ASCII and binary storage formats
STL Data format
Stereo Lithography format widely used in CAD/CAM, Rapid Prototyping,etc
Data consists of triangulated facets ( triangles ) that approximate the surface of the solid
Facet normal are also available
ASCII and binary storage formats
facet normal e e e+000
outerloop
vertex e e e+000
vertex e e e+000
vertex e e e+001
endloop
endfacet

13. To create surface/brep directly/indirectly from the 3D ASCII data
STL Mesh Data Object
STL data used as input for generating Rapid Prototype models as well as for NC toolpath generation.
To create surface/brep directly/indirectly from the 3D ASCII data
Creating a STLMesh object to save the data
Generation of a freeform entity representing the BRep

14. CollabCAD -> PointCloud : Import
Import 3D ASCII/STL ASCII or binary data from file and create a PointCloud object
Display of bounding box
Computation of no. of points

15. CollabCAD -> PointCloud : Import File Chooser
Import data formats
File chooser for STL ascii/binary formats

16. CollabCAD -> PointCloud : Information and bounding box
PointCloud bounding box
Display of bounding box
Bounding Box parameters

17. CollabCAD -> PointCloud : Cross-section points
CADPointCloud entity editing
Create a subset by getting points in a cross-section
Define the cross-section plane with tolerance

18. Point Cloud : 3D point ASCII data – Surface fit
Import 3D point ASCII data
Creates CADPointCloud entity
Fit a surface using CADPointCloud
Appropriate to build geometry of open surfaces

19. CollabCAD® : Modules Design and Drafting
Surface Modeling and re-generation of curves and surfaces, analysis
Solid Modeling using primitives, Boolean operations, form features, Constraint based design
Reverse Engineering using 3D ASCII/STL/IGES data
Collaborative Design using Intranet or VPN technology
Database Connectivity with geometric entities
Data Exchange using IGES, STEP, VRML
NC operations like roughing, milling, drilling, threading,etc
Customization of GUI using XML (open data standard )
Programmable Scripting Interface using Jython

20. CollabCAD® : Basic and Curves
Basic (2D)
Creation of Points, Lines, Arcs, Rectangle, 2D Constrained Profile, Free-hand Sketch
Curves (2D/3D)
Creation of Ellipses, Parabolas,Hyperbolas, Helix, Involutes, B-Splines
B-Splines by approximation, blending, interpolation, extending, converting, projection, concatenate, splitting

21. CollabCAD® : Surface Modeling
Creation and modification of Planes, Cylindrical, Conical, Spherical, Toroidal to more advanced B-Splines, pipe, revolution and extruded surfaces.
Creation of Offset, Ruled, Fillet, Lofted and Trimmed surfaces.
Local properties and display of surface normal
Cross-section slicing along line/plane, multiple slices

22. CollabCAD : Tools
PointCloud Import/Editing/Re-creation of curves/surfaces
Analysis of curves, surfaces, solids for its properties

23. Curvature Analysis on any curve
Display Curvature analyze and display curvature markers
Graphical Representation of the curvature and parameters

24. Curvature Analysis on any surface
Any geometrical surface can be evaluated for curvature’s along U an V parameterization
Both graphical and tabular results

25. Aircraft surface model : fuselage section
Fuselage section of aircraft model
Cross-section points data imported
Curve/surface model generated by lofting operation

26. Curvature analysis and scaling of boundary curves
Curves are scaled at each section
Radius of curvature analysis and parameterization on curves ( tabular and graphical representation)
XY Plotting tool

27. Aircraft surface model recreated from cross-section data
ASCII data provided in the form of No. of cross-sections and points in each cross-section
Generate points
Fit/approximate 3d curves
Build surface by approximation/lofting

28. CollabCAD : Scaling of entities
Scale : Uniform and Differential
Increase/decrease the size of a model uniformly or set in X or Y or Z direction

29. Scaling of curves and surfaces
Curves are uniformly scaled at each section
Scaling options about Entity-origin, Arbitrary Point, Coordinate system

30. Slicing of geometry and generation of cross-section point data
Surface and solid geometry can sliced to get the boundary curves
Single cross-section along line, plane, Normal to any axis
Generate hatching pattern
Multiple cross-sections slicing at different planes/offsets
Generate sectional data and write to ASCII file

31. CollabCAD : Pump model recreated from STL data
Wire frame display of Brep
STL ASCII file imported to create a Brep model
Shaded view

32. CollabCAD : BRep model of the Pump

33. CollabCAD : BRep model of Tea Pot
STL ASCII data : 2016 triangles

34. CollabCAD : BRep model of Bottle (STL file)

35. CollabCAD : BRep model of Propeller
STL Binary data file imported

36. CollabCAD : Context based Search and Help

37. Q and A (Please fill in the Feedback form)

38. Thank you www.collabcad.com