Free butterflies software for linux

MeshLab is an extendible system for the user assisted processing 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 cleaning and healing this kind of meshes.
The system is heavily based on the VCG library developed at the Visual Computing Lab of ISTI - CNR, for all the core mesh processing task.
The Meshlab system started as a part of the FGT course of the Computer Science department of University of Pisa.
Main features:
- Input/output in many formats (PLY, STL, OFF, OBJ)
- Extendible plugins based architecture, writing new mesh processing functions, colorization filters and support for different file formats is quite easy.
- Cleaning Filters
- Removal of duplicated, unreferenced vertices, null faces
- Subdivision filters (loop and butterfly)
- Opengl Shader based rendering
- Large snapshot for hi quality printing
- Various Colorization Filters
- Gaussian curvature
- Border edges
- Non two-manifold faces
Enhancements:
- This release adds various new filtering tools and exposes more options for existing filters.
- The stability and robustness of I/O mesh filters have been greatly improved.
- Various kind of non-standard variations of known formats are now also parsed.
- Automatic cleaning of loaded STL was added.
- A major enhancement is the powerful interactive painting system that allows you to interactively change the color of a mesh, define selections, and even directly smooth out noise and small features.