external: it contains a series of external libraries needed by several plugins. Some of these libraries are compiled before the compilation of meshlab, if a corresponding system library is not found and then linked; some other libraries are just included by some plugins.
common: a series of utility functions used by MeshLab and its plugins.
meshlab: GUI and core of MeshLab.
meshlabserver: a tool that allows to compute mesh operations through command line
meshlabplugins: all the plugins that can be added to MeshLab.

The following folders are used by cmake:

cmake;
templates.

There are also two folders that contains MeshLab plugins that are no longer supported or are experimental, and these plugins are not compiled in any of MeshLab configurations:

plugins_experimental;
plugins_unsupported.

Compiling MeshLab

MeshLab compiles with the three major compilers: gcc, clang, and msvc.

MeshLab requires Qt >= 5.9, with xmlpatterns as additional package.

After setting up the Qt environment:

git clone --recursive https://github.com/cnr-isti-vclab/meshlab
cd meshlab/src
qmake
make

Then, a meshlab executable can be found inside the distrib folder.

You can also use cmake:

git clone --recursive https://github.com/cnr-isti-vclab/meshlab
cd meshlab
cmake src/
make

You can also use QtCreator to build meshlab:

Install QtCreator and Qt >= 5.9 with xmlpatterns as additional package;
Open meshlab.pro inside src;
Select your favourite shadow build directory;
Before the build, deactivate the QtQuickCompiler option from the qmake call in the project options;
Build meshlab.

MeshLab has a plugin architecture and therefore all the plugins are compiled separately; some of them are harder to be compiled. Don't worry, if a plugin fails to compile just remove it and you lose just that functionality. As a first step you should try to compile MeshLab with the configuration "meshlab_mini":

qmake "CONFIG+=meshlab_mini"
make

This configuration contains the info for building meshlab with a minimal set of plugins.

Some plugins of MeshLab need external libraries. All the required libraries are included in the meshlab/src/external folder, that are automatically compiled before MeshLab in all its configurations.

Platform specific notes

On osx some plugins exploit openmp parallelism (screened poisson, isoparametrization) so you need a compiler supporting it and the clang provided by xcode does not support openmp. Qmake is configured in order to look for the clang compiler that is automatically installed by homebrew, calling:

brew install llvm libomp

On Linux, you may optionally choose to use your system installs of some libraries rather than the bundled versions. The library name, argument to add to all qmake calls (e.g. by adding to QMAKE_FLAGS in the example below), and Debian package name are listed below:

Eigen3 (at least 3.2) - CONFIG+=system_eigen3 - package libeigen3-dev
GLEW (version 2 or newer) - CONFIG+=system_glew - package libglew-dev
lib3ds - CONFIG+=system_lib3ds - package lib3ds-dev
OpenCTM - CONFIG+=system_openctm - package libopenctm-dev
BZip2 - CONFIG+=system_bzip2 - package libbz2-dev

The versions found in Debian Buster are all new enough to meet these requirements.