Sketch Interpretation System - Index

These pages present methods for the automatic creation of boundary representation models of polyhedral objects from single line drawings depicting the objects. This topic is important in that automated interpretation of freehand sketches would remove a bottleneck in current engineering design methods. The thesis does not consider methods which require manual intervention or multiple drawings.


In engineering and scientific development, it is normal that a break-through relieving an immediate bottleneck serves to either create or reveal another (Grace Hopper, 1959).


Automatic Creation of Boundary Representation Models from Single Line Drawings

Introduction

  • Introduction and Context
  • Terminology
  • Previous Investigations
  • Discussion of Aims
  • Structure

    Problem Statement and Proposed Solution Overview

  • Problem Statement
  • Alternatives and Possible Extensions
  • Solution Overview
  • Line Labelling
  • Subgraphs and Regions
  • Component: Parallel Lines
  • Component: Two-Dimensional Tidying
  • Component: Feature Identification
  • Component: Inflation
  • Component: Validation of Labelling
  • Component: Local Symmetry
  • Component: Classification
  • Component: Topological Reconstruction
  • Component: Face Loops
  • Component: Geometric Finishing
  • Component: Splitting and Recombination
  • Component: Intersecting Faces
  • Component: Quality Control
  • Chosen Components: Order and Control Structure

    Background Ideas

  • Sketch to Drawing
  • Searching and Heuristics
  • Constraints and Optimisation
  • Least Squares Fit
  • Planar Geometry
  • Solid Geometry
  • Dual Space
  • Miscellaneous

    Sketching and Conversion of Sketches to Line Drawings

    Line Labelling

  • Introduction
  • History
  • Tetrahedral Junction Catalogue
  • Two Labelling Approaches
  • Results
  • Extended Vertices: A Problem for Line Labelling
  • Conclusions

    Parallel Lines

  • Introduction
  • History
  • Reproduction of Bucketing
  • Partitioning into Bundles
  • Corners and Face Planes
  • Results and Recommendations
  • Special Sets of Parallel Lines

    Features

  • Introduction
  • History
  • Implementation
  • Underslots and Valleys
  • Cofacial Configurations
  • Hole Loops from Cofacial Configurations
  • Results

    Inflation

  • Introduction
  • History
  • Compliance Functions
  • Grimstead's Linear System Approach
  • Depth from Labelling
  • Results and Conclusions

    Frontal Geometry

    Local Symmetry Detection

  • Introduction
  • History
  • Compatibility, Pairing, Propagation
  • Figures of Merit
  • Data Identified
  • Mirror Chains
  • Results

    Classification

  • Introduction
  • History
  • Classes
  • Combining Classes
  • Results

    Reconstruction of Hidden Topology

  • Introduction
  • History
  • Number of Possible Completions
  • Control Mechanism
  • Move Types
  • Hypothesising Moves
  • Hypothesis Adjudication
  • Special-Case Recovery of Topology of Hidden Parts
  • Results

    Geometric Finishing

  • Introduction
  • History
  • Constraints
  • Face Normals: Simple Downhill Optimisation
  • Face Normals: Enhanced Downhill Optimisation
  • Face Normals: Geometric Optimisation
  • Face Normals using a Genetic Algorithm
  • Face Distances: Simple Downhill Optimisation
  • Face Distances: Enhanced Downhill Optimisation
  • Intersecting Faces
  • Special Classes
  • Results

    Results

  • Axis-Aligned Extrusion
  • Axis-Aligned Non-Extrusion
  • Grimstead's Block
  • Hole Loop
  • Extended Trihedral Normalon
  • Non-Trihedral Semi-Normalon
  • Semi-Normalon
  • Semi-Normalon
  • Non-Trihedral Semi-Normalon
  • Non-Trihedral Bracket
  • Conclusions
  • Timing

    Curved Objects

    Conclusions

  • Introduction
  • Line Drawing Interpretation
  • Sketch to Line Drawing
  • Features

    Psychology

    Appendices

    Glossary

    Test Drawings

    Tuning Constants

  • Tuning: Configurable Constants
  • Tuning: Introduction
  • Tuning for the Labelling Problem

    Figures of Merit

    Junction Catalogue Illustrations

  • Trihedral Catalogue
  • Tetrahedral Catalogue

    Geometric Analysis

  • Rotation Axis from Start and End Points and Angle

    Bibliography


    Funding for the more recent part of this investigation (i.e. everything since my PhD Thesis) was provided by Japan Society for the Promotion of Science Fellowship number P03717; this support is acknowledged with gratitude. Funding for future research comes from the Ramon y Cajal Programme, which support is also acknowledged with gratitude.


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