Reverse Engineering of The Taj Mahal- An Abstract of The Project The Taj Mahal at Agra, India is one of the wonders of the world. The Taj Mahal is Considered as World Heritage Site. The Taj Mahal is a Symbol of True Love.

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2. SIX D INDIA
Design Team
Mr. Sangiba Longchar: Head Design
(Reverse Engineering)
Mr. Joginder Saini: Sr. Design Engineer
(Rendering and Texturing)
Mr. Yogendra Kumar: Sr. Design
Engineer (CAD Modeling Expert)
Project Members
Mr. Pawan Panchpal : Project
Director(Technical)
Mr. Akash Rana : Project Manager
(Business)
Mr. Rajnish Ojha : Manager (Technical
Services)
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3. Terminology (Abstract )
 3D Scanning and Laser Scanning
 3D CAD Modeling (Reverse Engineering)
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4. 3D Scanning - Abstract
3D Scanning and data capture encompasses a number of similar technologies, all of which
can be considered optical 3D measurement techniques (or 3D imaging systems), which
describes an optical instrument that captures physical data from the environment, either
by speed/coherence of light or triangulation (not addressed in this document). Data
captured by 3D scanners are usually referenced with known Cartesian (XYZ) coordinate
systems, such as Global Navigation Satellite Systems (GNSS), Ordnance Survey (OS), or
local project coordinates. A number of industry terms are used to differentiate the ways
that data can be captured, processed and delivered.
3D Laser Scanning is a broadly applicable technology for a number of industries adopted
in the architecture, engineering, and construction (AEC).3D Laser scanning-terrestrial,
mobile or aerial 3D range imaging device that uses a laser (light) to measure distance via
time-of-flight, phase-based, or light-based detection. Common terms used in the AEC
industry include:
1. LIDAR (Light detection and ranging)- a term commonly used for aerial
scanners
2. LADAR (Laser detection and ranging)- commonly used for terrestrial
scanners
3. Flash LADAR/LIDAR- emission and detection of light using light arrays and
an electro-optical device
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5. 3D CAD Modeling (Reverse Engineering) - Abstract
Reverse Engineering is the practice of analyzing an object or system with the intent of
replicating it or understanding how it functions. Reverse engineer can be Applied in the
architecture, engineering, and construction (AEC), Organic compound, software
program, or a process. Reverse engineering is the opposite of forward engineering. It
takes an existing object or system and creates a CAD Model. Reverse engineering is
usually undertaken in order to redesign the system for better maintainability or to
produce a copy of a system without access to the design from which it was originally
produced.
Reverse Design finds wide Applications in:
 Duplicating a Physical Product for which no Technical Drawings or CAD data exists
 Developing a new product with enhanced functions based on an existing product
 Designing a Product from a Mock-up Model or Clay Model in the Automotive Industry, where
Aesthetic Design factors are critical
 Reconstructing, Preserving and Analyzing Cultural and Historical Assets
 Mass Customization of Products associated with the Living bodies (Human , Animals and
Organic)
 Using Digitized Information for Animation
 Manufacturing a products in the Medical and Dental fields
 Analyzing The Design Intent from Competitors' Products
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6. Reverse Modeling Process is the process of creating an optimal 3D model from 3D scan
data (Point Cloud or Mesh), that is generated during the Scan Data Processing phase.
This process is the core of Reverse Design, where optimized mesh and 3D features, such
as 3D curves, 3D surfaces, and 3D solid bodies, are created by using various modeling
methods. The Mesh Modeling method creates an optimized mesh that contains
important information by applying various geometric and mathematical operations. The
Feature Modeling method creates 3D geometric feature shapes based on extracted design
intent and elements from 3D scan data The Fitting Surface Modeling method creates
fitted freeform surfaces on complex freeform feature shapes. The Hybrid Modeling
method creates a complex feature model from 3D scan data by using the Feature
Modeling method in conjunction with the Fitting Surface Modeling method.
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7. The Design Process - Abstract
1. Patch PTS (PointCloud) to Patch STL (SteroLithography)Data Processing:
2. Patch STL to Final Merged STL Data Processing:
3. Merged STL Data to CAD Model Processing:
 Structure Based CAD Modeling
 Feature Based CAD Modeling
4. Final Assembly of CAD Models
Important Pre Requisite Before The Design Process:
 Positioning and Aligning of the Taj Mahal wrt The Mosque(West), The Guest
House(East) and The Great Gate (South).
 Positioning and Aligning wrt The Geographical Co-ordinates.
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8.  Post registration Data of 3D Laser Scanning in pts (PointCloud) file extension
is Processed and converted into STL (SteroLithography) file extension.
 Processing is done in patch by patch as shown in picture below. Resulting in a Single
STL Patch.
 This is an automatic Algorithmic Process which results in Useable and Editable STL file
extension.
Patch STL No 1 Patch STL No 2 Patch STL No 3 Patch STL No 4
Patch PTS (PointCloud) to Patch STL (SteroLithography) Processing:
Patch STL (SteroLithography) after Processing:
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9. All Useable and Editable STL Patches (Picture on
Left side are Merged into a Single Water Tight
STL Data (Picture on the Right Picture ).
 This Process Executes
 Hole Filling.
 Noise Removal.
 Feature Editing.
 Polygonal Mesh Repair.
 Decimates no of triangles .
 Data Merging
 Final Output Data is Exported in STL File
format for Further Processing in CAD
Environment.
Final Merged STL (Front View)
Final Merged STL (Isometric View)
Patch STL to Final Merged STL Data Processing
STL Patches
To
Merged STL
STL Patches
To
Merged STL
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10.  Structure Based CAD Modeling
 Feature Based CAD Modeling
Structure Based CAD Modeling
 Major and Minor Structures are identified.
 Final Merged STL is Imported into CAD Environment for Design Intent.
 Sections of the STL Data are generated and Transferred to Sketch Mode.
 2D Sketch are generated and Transferred into CAD Mode.
 Using Appropriate Tools and Commands 3D CAD is developed as per the STL Data.
Merged STL Data to CAD Model Processing:
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11. STL Cross Section 2D Sketch Drawings 3D CAD Model
STL Cross Section 2D Sketch Drawings 3D CAD Model
Structure Based CAD Modeling of Minarets:
Structure Based CAD Modeling of Main Dome:
STL Section
To
2D Sketch
2D Sketch
To
3D CAD
STL Section
To
2D Sketch
2D Sketch
To
3D CAD
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12. Feature Based CAD Modeling
 Major and Minor Features are identified.
 Final Merged STL is Imported into CAD Environment for Design Intent.
 Sections of the STL Data are generated and Transferred to Sketch Mode.
 2D Sketch are generated and Transferred into CAD Mode.
 Using Appropriate Tools and Commands 3D CAD is developed as per the STL Data.
Merged STL Data to CAD Model Processing:
Feature Based CAD Modeling of Wall Carvings:
STL Cross Section 2D Sketch Drawings 3D CAD Model
2D Sketch
To
3D CAD
STL Section
To
2D Sketch
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13. Final Assembly of CAD Models
 Assembly of Structured based 3D CAD
and Featured based 3D CAD are Merged
together to Develop The Final 3D CAD
Model.
Structured based 3D CAD Merged
to
Final CAD
Featured based 3D CAD
to
Final CAD
Final 3D CAD Model (Front View) Final 3D CAD Model (Isometric View)
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14. THANK YOU
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