Computational Conformal Geometry Library - CCGL
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Introduction

Getting CCGL
    Download
    Installation


Development Guide
    Architecture
    Performance


Gallery
    Snapshots
    Movies

Mesh Data Structure
    Viewer

Topology
    Cut Graph
    Slicer
    Double Cover
    Homology Basis

Conformal Maps
    Harmonic Map
    Spherical Harmonic Map
    LSCM

Holomorphic 1-Form
    Integration
    Harmonic 1-Form
    Holomorphic 1-Form
    Slit Map

Curvature Flow
    Euclidean Ricci Flow
    Poly Annulus Ricci Flow
    Hyperbolic Ricci Flow
    Yamabe Flow

Documentation
    Reference Book

Acknowledgements
Harmonic 1-Form

heads
heads
heads
heads
eight.open_0.m
eight.open_1.m
eight.open_2.m
eight.open_3.m
heads
heads
heads
heads
eight.u_0.m
eight.u_1.m
eight.u_2.m
eight.u_3.m

Algorithm Description

Harmonic 1-form algorithm computes harmonic 1-forms on a high genus closed surface. According to Hodge theory, each cohomologous class has a unique harmonic form. The algorithm is linear.

heads
eight.m
Input and output

There are two input meshes:

  • A high genus closed mesh, e.g. the genus two eight.m.
  • The mesh is sliced open along a homology basis loop, e.g. eight.open_0.m.


There are two output mesh:
  • The closed mesh with harmonic 1-form recorded as edge traits eight.w_0.m.
  • The mesh cut along the homology basis with uv coordinates, which are obtained by integrating by the harmonic 1-form, e.g. eight.u_0.m.

Convergence, Stability and Efficiency

The computational process is stable and converges fast.

Example

   The input genus two mesh has 7k faces. The computational time is about 2 seconds on a PC with 3.0 GB of RAM, 3.60 GHz CPU. The data set and the source can be downloaded.

Command

  1. Compute the homology group basis:

    homology.exe eight.m eight.open

    This generates eight.open_0.m eight.open_1.m eight.open_2.m eight.open_3.m
  2. Compute the harmonic 1-forms:

    harmonicform.exe eight.m eight.open_0.m eight_w_0.m eight.u_0.m
    harmonicform.exe eight.m eight.open_0.m eight_w_1.m eight.u_1.m
    harmonicform.exe eight.m eight.open_0.m eight_w_2.m eight.u_2.m
    harmonicform.exe eight.m eight.open_0.m eight_w_3.m eight.u_3.m