MeshDev from Michael Roy
MeshDev software compares two triangular meshes according to the geometrical data or appearance attribute data. It returns visual and numerical results. Mesh difference assessment uses the Attribute Deviation Metric. Attribute deviation assessments allow one to highlight local differences between two meshes.

Home Page: http://meshdev.sourceforge.net/

MeshLab
MeshLab is an open source, portable, and extendible system for the processing and editing of unstructured 3D triangular meshes. The system is aimed to help the processing of the typical not-so-small unstructured models arising in 3D scanning, providing a set of tools for editing, cleaning, healing, inspecting, rendering and converting this kind of meshes.

Home Page: http://meshlab.sourceforge.net/

Metro from CNR-Pisa
Metro is a tool to evaluate the difference between surfaces (e.g., a triangulated mesh and its decimated representation). Metro adopts an approximated approach based on surface sampling and approximated point--surface distance computation. It returns both numerical results (maximum and mean error, volume difference, surface difference, etc.) and visual results, by coloring the input surface according to the approximation error.

Home Page: http://vcg.sourceforge.net/tiki-index.php?page=Metro

M.E.S.H. from Nicolas Aspert
MESH (Measuring Error between Surfaces using the Hausdorff distance) is a tool that measures distortion between two triangular meshes. It uses the Hausdorff distance to compute maximum, mean, and root-mean-square errors between two given surfaces. MESH can also display the error values on the surface itself.

Home Page: http://mesh.epfl.ch/

ZipPack by the Stanford Graphics Lab
The ZipPack Polygon Mesh Zippering package combines range images into a polygonal mesh. It was specifically created to more fully use range images acquired from a Cyberware range scanner. This utility was used for a SIGGRAPH 1994 paper by Greg Turk and Marc Levoy.

Home Page: http://www-graphics.stanford.edu/software/zippack/

Ply Filters by Greg Turk and others
This package contains a collection of geometry filters that support the .ply file format for 3D objects, a popular file format used for 3D models in the level of detail research field. This includes conversion, processing, and generation utilities. It also includes documentation on the .ply format.

Home Page: http://www.cc.gatech.edu/projects/large_models/ply.html
Source Code: http://www.cc.gatech.edu/projects/large_models/files/ply.tar.gz

Ply Utilities from UNC
This package contains complete source code for a number of utilities that support the .ply file format, such as triangulation, vertex collapsing, vertex and face removal, etc. It is supplied by the Department of Computer Science at the University of North Carolina at Chapel Hill.

Home Page: http://www.cs.unc.edu/~geom/Powerplant/
Source Code: http://www.cs.unc.edu/~geom/Powerplant/zips/ply_utilities.zip

Qhull from the Geometry Center, UMN
Qhull computes convex hulls, Delaunay triangulations, halfspace intersections about a point, Voronoi diagrams, furthest-site Delaunay triangulations, and furthest-site Voronoi diagrams. It runs in 2-d, 3-d, 4-d, and higher dimensions. It implements the Quickhull algorithm for computing the convex hull.

Home Page: http://www.geom.umn.edu/software/qhull/

Triangulation Code by Atul Narkhede and Dinesh Manocha
This source code is part of a Graphics Gem called "Fast Polygon Triangulation based on Seidel's Algorithm." It is an incremental randomized algorithm that in practice works in linear time to take a polygon having n vertices and decompse this into n-2 triangles. The code also deals with simple polygons that contain holes.

Home Page: http://www.cs.unc.edu/~dm/CODE/GEM/chapter.html
Source Code: UNC FTP site

GeoVRML Code by Martin Reddy and others
The GeoVRML effort provides geospatial coordinate systems and terrain-specific level of detail functions to standard VRML97. These is implemented as EXTERNPROTOs with Java in Script nodes. The full Java source code for GeoVRML is freely available. The GeoLOD node provides support for large terrain LOD.

Home Page: http://www.geovrml.org/
Source Code: http://www.geovrml.org/1.0/source/

Percept by Martin Reddy
This simple utility attempts to visualize the limits of vision in an intuitive manner. The program reads an input image and processes this to create another image showing the degree of detail actually visible to the human eye for any given field of view. C source code is provided.

Home Page: http://www.MartinReddy.net/percept/

Avalon Software
Th Avalon 3D Archive contains a number of useful software tools. This includes translators for various file formats, a range of utility software, and viewers for different formats.

Home Page: http://avalon.viewpoint.com