Changelog

Version Summary Table

Click to unroll.

Version	Short description
main	…
2.4.0	Bug fixes, CMake tidying, imgui widgets, broad M1 mac support, dependency bumps
2.3.0	Dual Contouring, DDM skinning, Bézier, PLY reader, 3D text rendering, matcap
2.2.0	New python bindings, fast winding number for soups, ICP algorithm
2.1.0	Various improvements and bug fixes, updated dependencies
2.0.0	Lighter, simpler CMake build, rewritten history
1.3.3	Switched the build system from submodules to CMake external projects
1.3.2	After merging PRs in the 2018 hackaton
1.3.1	Before merging PRs in the 2018 hackaton
1.3.0	Modernized cmake build, multi-mesh viewer, replace nanogui with imgui
1.2.1	Reorganization opengl-dependent functions: opengl and opengl2 extras
1.2.0	Reorganization of “extras”, rm deprecated funcs, absorb boost & svd3x3
1.1.7	Switch build for static library to cmake.
1.1.6	Major boolean robustness fix, drop CGAL dependency for AABB/distances
1.1.5	Bug fix in booleans
1.1.4	Edge collapsing and linear program solving
1.1.3	Bug fixes in active set and boundary_conditions
1.1.1	PLY file format support
1.1.0	Mesh boolean operations using CGAL and cork, implementing [Attene 14]
1.0.3	Bone heat method
1.0.2	Bug fix in winding number code
1.0.1	Bug fixes and more CGAL support
1.0.0	Major beta release: many renames, tutorial, triangle, org. build
0.4.6	Generalized Winding Numbers
0.4.5	CGAL extra: mesh selfintersection
0.4.4	STL file format support
0.4.3	ARAP implementation
0.4.1	Migrated much of the FAST code including extra for Sifakis’ 3x3 svd
0.4.0	Release under MPL2 license
0.3.7	Embree2.0 support
0.3.6	boost extra, patches, mosek 7 support, libiglbbw (mosek optional)
0.3.5	More examples, naive primitive sorting
0.3.3	Many more examples, ambient occlusion with Embree.
0.3.1	Linearly dependent constraints in min_quad_with_fixed, SparseQR buggy
0.3.0	Better active set method support
0.2.3	More explicits, active set method, opengl/anttweakbar guards
0.2.2	More explicit instantiations, faster sorts and uniques
0.2.1	Bug fixes in barycenter and doublearea found by Martin Bisson
0.2.0	XML serializer more stable and fixed bug in remove_duplicate_vertices
0.1.8	Embree and xml (windows only) extras
0.1.5	Compilation on windows, bug fix for compilation with cygwin
0.1.1	Alpha release with core functions, extras, examples

Upcoming Version 2.5.0 Changes

The following changes are represent in the main branch of libigl, but not yet included in a tagged release.

Bugfixes

• ViewerData::set_data() now accepts #F-long data vectors (1f44d1e)

Enhancements

• ismember_rows split into its own file (may need to change #include <igl/ismember.h> to #include <igl/ismember_rows.h> (#1989)
• igl::predicates::delaunay_triangulation and igl::predicates::lexicographic_triangulation routines (#1988)
• properly expose edge-markers in igl::triangle::triangulate (#1983)

Compilation

Version 2.4.0 Changes

Breaking Changes

Libigl v2.4.0 introduced a number of breaking changes regarding its CMake build system. If you follow the upgrade guide below, these breaking changes should be easy to resolve.

Tip

When starting a new project using libigl, use the libigl-example-project as a starting point.

CMake entry point

The main entry point for CMake is now the CMakeLists.txt at the root of the libigl repository. If you were using a FindLibigl.cmake, or were including libigl.cmake directly, please update your project.

If you are using the libigl-example-project, you may update the content of cmake/libigl.cmake to the following:

if(TARGET igl::core)
    return()
endif()

include(FetchContent)
FetchContent_Declare(
    libigl
    GIT_REPOSITORY https://github.com/libigl/libigl.git
    GIT_TAG <TARGET_SHA1>
)
FetchContent_MakeAvailable(libigl)

CMake targets

The CMake targets for many libigl modules have been renamed in v2.4.0. This provides greater visibility into each module category (between regular, copyleft and restricted modules). Here is the table mapping the old names to the new names:

Old target name (v2.3.0)	New target name (v2.4.0)
igl::embree	Unchanged
igl::opengl_glfw	igl::glfw
igl::opengl_glfw_imgui	igl::imgui
igl::opengl	Unchanged
igl::png	Unchanged
igl::predicates	Unchanged
igl::xml	Unchanged
	igl_copyleft::core (New)
igl::cgal	igl_copyleft::cgal
igl::comiso	igl_copyleft::comiso
igl::cork	Removed
igl::tetgen	igl_copyleft::tetgen
igl::matlab	igl_restricted::matlab
igl::mosek	igl_restricted::mosek
igl::triangle	igl_restricted::triangle

Important

The libigl cork wrapper was removed from this release. A standalone repository with a libigl-style wrapper around cork is available here.

CMake options

Many libigl CMake options have changed in v2.4.0. Here is a mapping from the old name to the new names:

Old option (v2.3.0)	New option (v2.4.0)
	LIBIGL_COPYLEFT_CORE (New)
LIBIGL_BUILD_TESTS	Unchanged
LIBIGL_BUILD_TUTORIALS	Unchanged
LIBIGL_EXPORT_TARGETS	LIBIGL_INSTALL
LIBIGL_USE_STATIC_LIBRARY	Unchanged
LIBIGL_WITH_CGAL	LIBIGL_COPYLEFT_CGAL
LIBIGL_WITH_COMISO	LIBIGL_COPYLEFT_COMISO
LIBIGL_WITH_CORK	Removed
LIBIGL_WITH_EMBREE	LIBIGL_EMBREE
LIBIGL_WITH_MATLAB	LIBIGL_RESTRICTED_MATLAB
LIBIGL_WITH_MOSEK	LIBIGL_RESTRICTED_MOSEK
LIBIGL_WITH_OPENGL	LIBIGL_OPENGL
LIBIGL_WITH_OPENGL_GLFW	LIBIGL_GLFW
LIBIGL_WITH_OPENGL_GLFW_IMGUI	LIBIGL_IMGUI
LIBIGL_WITH_PNG	LIBIGL_PNG
LIBIGL_WITH_PREDICATES	LIBIGL_PREDICATES
LIBIGL_WITH_PYTHON	Removed
LIBIGL_WITH_TETGEN	LIBIGL_COPYLEFT_TETGEN
LIBIGL_WITH_TRIANGLE	LIBIGL_RESTRICTED_TRIANGLE
LIBIGL_WITH_XML	Unchanged

Tip

There is a now a sample file LibiglOption.cmake.sample at the root of the libigl repository. Simply remove the .sample extension and edit this file to modify libigl compilation options. If you are using libigl as a subdirectory (e.g. in a parent project), then please set your options in the parent project instead.

ImGui headers

We are also updating our ImGui dependency to use the base repository as include folder, rather than forcing headers to be copied into a imgui/ subfolder. This helps be consistent with other projects that might be using ImGui. This requires users changing their include headers as follows:

• #include <imgui/imgui.h> → #include <imgui.h>
• #include <imgui/imgui_internal.h> → #include <imgui_internal.h>
• #include <imgui_impl_glfw.h> → #include <backends/imgui_impl_glfw.h>
• #include <imgui_impl_opengl3.h> → #include <backends/imgui_impl_opengl3.h>

ImGuiMenu,ImGuizmoPlugin,SelectionPlugin → ImGuiWidgets

We’ve introduced a new “parent” ImGuiPlugin which handles ImGui IO functions and converted the old ImGuiMenu, ImGuizmoPlugin, SelectionPlugin plugins to inherit from a new ImGuiWidget class. In this way, a single ImGuiPlugin can be registered to the viewer’s plugins list and one or many widgets are registered to this plugin’s widgets list.

For folks just using the menu, this incurs a few extra lines. To add the menu:

#include <igl/opengl/glfw/imgui/ImGuiPlugin.h>
#include <igl/opengl/glfw/imgui/ImGuiMenu.h>
…
igl::opengl::glfw::imgui::ImGuiPlugin plugin;
viewer.plugins.push_back(&plugin);
igl::opengl::glfw::imgui::ImGuiMenu menu;
plugin.widgets.push_back(&menu);

The reward is that now we can use all of these plugins (and any new user created plugins using ImGui subroutines) without conflict.

Other Changes

Bugfixes

• Fix #1656 “Can only have one ImGuiMenu plugin at a time” (#1973)
• Fix #1924 “PLY with no faces throw SIGFPE in ReadPLY” (#1927)
• LSCM: fix sign for the area term (#1853)
• Fix bug in igl::read_file_binary (#1821)
• Fix #1795 “Can’t convert CGAL::Polyhedron_3 to mesh” (#1796)
• Fix the order of principal curvature (#1767)
• Fix dirty flag for ViewerData::set_labels (#1761)

Enhancements

• Modified arap interface to accept Eigen::Map (#1922)
• Wrapper around CGAL’s 2D constrained delaunay triangulation (#1811)
• Delete obsolete function igl::point_in_poly (#1810)
• Instead of calling exit(1), triangle now throws an exception (#1800)
• Use igl::default_num_threads in cgal module (#1768)
• Added double_sided flag to embree renderer (#1765)
• Replace Eigen::PlainObjectBase with Eigen::MatrixBase for input of ambient_occlusion (#1752)
• 10-100x speedup on per corner normals + caching adjacency (#1745)

Compilation

• Update Catch2 to v2.13.8 (#1972)
• Update Embree to v13.3.3 (#1976)
• Broad support for M1 macs (#1976, #1975)
• Update ImGui to v1.85 + use default include folders for ImGui (#1970)
• CMake refactor (#1805)
• CGAL and Boost are now built entirely from source via CMake. This means the CGAL module will work out of the box under Windows – no need for a conda virtual environment. On Linux/macOS, the only dependency to install system-wide are GMP+MPFR.
• CMake targets and options have been renamed based on the module category: regular/copyleft/restricted. This eliminates long module names (igl::open_glfw_imgui) that didn’t bring much to the table, in favor of three root classes based on available licenses for each module.
• There is now a LibiglOptions.cmake sample file at the root of the project repository, which should make it easier to document/update available CMake options.
• There is now a unique entry point for the project, which is the root CMakeLists.txt. This facilitates maintenance, as before either tutorial/CMakeLists.txt and cmake/libigl.cmake could serve as potential entry points.
• The default behavior for module compilation is:
  • When compiling libigl on its own, all modules are enabled by default.
  • When compiling libigl as a subproject, all modules are disabled by default.
  • On Linux/macOS, if GMP/MPFR is not installed on the system, shows a warning and disable CGAL by default.
  • If Mosek/Matlab are not installed on the system, shows a warning and disable the Mosek/Matlab libigl wrappers respectively.
  • If the user explicitly enables those modules, but they do not have GMP/MPFR/Mosek/Matlab installed on the system, CMake configuration will fail.
• Big cleanup of the tutorial CMake definitions. With the new setup adding a new tutorial is even easier!
• Cleaned up dependency setup for imgui/stb (among others)
• Unit tests have been split into different CMake target, based on which module is tested.
• Add support for Hunter + install() for the igl::core module (should be the same as before).
• Use a more generic igl_copy_dll() function to copy GMP/MPFR dlls on Windows (should work to copy the CoMiSo dll as well).
• Cleaned up our .gitignore file.
• Fix blue noise random shuffle for C++17 (#1949)
• Bump triangle version (#1813) and tetgen version (#1815)
• Templates EmbreeRenderer (#1788)
• Fix Cuda compilation issue on Windows (#1747)
• Split min_quad_with_fixed implementation into separate cpp (#1746)
• Silence MSVC warning with std::getenv (#1744)
• Fix usage of find_package(OpenGL) on Linux (#1733)

Version 2.3.0 Changes

Warning

This is our last stable release before some planned major reorganization (see #1696 for details). The upcoming reorganization is aimed at facilitating maintenance and packaging of various libigl components. The next release will be a new major version of libigl (3.0.0).

New Features

• Dual contouring (#1716)
• Viewer: Selection Plugin (#1654)
• Implements “Polygon Laplacian Made Simple” (#1653)
• Offscreen meshes rendering using Embree (#1652)
• Signing distances with Fast Winding Number (#1630)
• Turn ImGuizmo tutorial into a viewer plugin (#1618)
• Adds MATLAB-like function igl::blkdiag to build a block-diagonal matrix (#1617)
• Kelvinlet mesh deformation (#1614)
• Blue noise sampling on triangle meshes + adds igl::barycentric_interpolation (#1597)
• Direct Delta Mush skinning (#1541)
• New exploded view tutorial (#1510)
• Bézier curve evaluation (igl::bezier) and fitting (igl::fit_cubic_bezier) (#1476)
• Replace .ply reader/writer with tinyply library (#1422)
• igl::copyleft::cgal::wire_mesh now support per-edge thickness. Adds igl::copyleft::cgal::coplanar test (#1488)
• New generic function for connected components (igl::connected_components) (#1487)
• Viewer: matcap support (#1482) + tutorial entry (#1646)
• Viewer: option for double-sided lighting (#1480)
• Viewer: new 3D text rendering feature, supporting proper label depth (#1549)

Build System

• Update ImGui to 1.81 (#1723), fixing rendering issue with newer Visual Studio
• Fix mosek to work with 9.2; fix mosek dynamic link via CMake (#1675)
• Reimplement igl::marching_cubes outside of the copyleft/ folder (#1666, #1687)
• Update GLFW to fix an issue on macOS with CMake 3.19.0 (#1657)
• Update Embree to v3.12.1 (#1648)
• Use new gitlab remote to clone Eigen (#1631)
• Update compiler versions in github actions (#1629)
• Update CoMiSo version (#1608). Note that CoMiSo support for libigl is deprecated and will be removed in version 3.0.
• Removed _bin suffix from executable files (#1594)
• Moved SCAF to triangle folder (#1590)
• Various fixes to github actions (#1649, #1651, #1721)

Misc

• Control number of threads in parallel_for with env variable IGL_NUM_THREADS (#1684)
• Support msh in igl::read_triangle_mesh (#1645)
• Change boundary weight from length to length squared in igl::per_vertex_point_to_plane_quadrics (#1644)
• Update STL read to work on problematic thingi10K meshes (#1628)
• Use an enum to specify file encoding when writing files (#1619)
• Removed some functions marked as deprecated (#1610)
• Fix bug with epsilon parameter in igl::remove_duplicate_vertices (#1603)
• Removed unused function igl::barycentric_to_global (#1596)
• Fix align_camera_center in Viewer::init() for multiple cores (#1349)
• Add floating point exceptions in unit tests (#1001)
• Extended serialization functionality to Eigen::Array (#1113)
• SCAF: Expose linear system to be solved by user code (#1553)
• Fix issue with igl::heat_geodesic (#1497)
• Refactored igl::is_edge_manifold (#1509)
• Various bugfixes, compile fixes, template fixes (#1335, #1361, #1400, #1402, #1430, #1438, #1441, #1471, #1475, #1484, #1494, #1495, #1497, #1525, #1538, #1544, #1546, #1581, #1582, #1625, #1627, #1638, #1640, #1642, #1658, #1673, #1674, #1679, #1694, #1704, #1709)

Version 2.2.0 Changes

Python Bindings

The python bindings have been moved to a separate repository. These are now available as an conda package.

New Features

• Fast winding number for triangle soups (#1218)
• Iterative closest point algorithm + tutorial (#1347)
• Ear clipping triangulation (#1169)
• Added igl::path_to_edges function (#1259)
• igl::dijkstra can now use mesh edge length (#1170)
• Keep reference to multiple material when reading obj (#1280)
• Added igl::sharp_edges for sharp edges extraction (#1364)
• Added igl::unproject_on_line, igl::unproject_on_plane and igl::projection_constraint to compute cursor (un)-projections (#1368)
• Added igl::quad_grid and igl::triangulated_grid to create meshes from regular grids (#1369)
• Added igl::isolines_map, ViewerData::set_data and ViewerData::set_colormap to improve scalar field visualization in the Viewer, and updated tutorials accordingly (#1371)
• Added new COLOR_MAP_TYPE_TURBO colormap, based on Turbo. Jet is now an alias for Turbo, and switched to Viridis as default colormap in the viewer (#1372)
• Added igl::slice_sorted and removed deprecated Eigen::DynamicSparsematrix from igl::slice (#1370)

Build System

• Overhauled function signatures in preparation of new python bindings (#1162, #1228, #1271, #1274)
• Added a conda environment cmake/libigl-cgal.yml to provide boost for Windows users (#1239)
• Added experimental support for Hunter (#1242)
• Now libigl.cmake will define a CMake target Eigen3::Eigen if not provided by the user (#1299)
• Added igl_set_folders() to sort CMake targets into folders in IDEs such as Visual Studio or Xcode (#1383)
• Minor fixes to our CMake build system (#1363)
• Github actions for CI replacing appveyor and travis (#1389)

Misc

• Fix underflow issue when computing normalization in igl::heat_geodesics (#1344)
• Update nrosy to match the MIQ paper (#1303)
• Delete Embree_convenience.h (#1314)
• Refactored igl::cut_mesh (#1332)
• Various improvements to the viewer (#1196, #1251, #1366)
• Unit tests: cleand up test_common.h (#1365)
• Made call to igl::predicates::exactinit() thread-safe + marked internal functions in predicates.c as static to prevent name collisions (#1377)
• Doc cleanup (#1376)
• Allows igl::hsv_to_rgb to work on negative hues (#1399)
• Explicitly marked the following functions as deprecated (#1380):
  • igl::all_edges
  • igl::internal_angles_using_edge_lengths (only a specific overload is affected)
  • igl::is_border_vertex (only a specific overload is affected)
  • igl::remove_duplicates
• Various bugfixes, code cleanup and explicit template instantiations (#1197, #1210, #1216, #1231, #1247, #1258, #1288, #1309, #1320, #1337, #1345, #1379, #1396, #1327)

Version 2.1.0 Changes

• Various code cleanup, compilation fixes, and explicit template instantiations
• Added wrapper around Shewchuk’s predicates (#1163)
• libigl now also compiles with Eigen 3.3 (#1110).
• Extended igl::cat functionalities (#1108)
• Extended boundary_facets with outputs revealing which element facet comes from (#1067)
• Use std::shuffle instead of std::random_shuffle in igl/randperm (#1062)
• Fixed an Eigen alignment issue in the viewer (#1029)
• Removed LIM tutorial (#1012, #1014)
• Fixed current python bindings (#1008)
• Intrinsic Delaunay triangulation (#988)
• New Heat Geodesics feature (#988, #1140). See also tutorial 716.
• Switched from Google Test to Catch2 (#961), and added various unit tests
• Fixed an issue with transparent window on macOS that was introduced in v2.0.0 (#953)
• Updated dependencies: Embree 3 (#947), GLFW (#977, #1153), ImGui (#1039), std-image (#1072)
• Added sparse voxel grids (#937, #942) and tutorial 715 for meshing implicit functions.
• Added tutorial 714 for marching tets (#716)

Version 2.0.0 Changes

This release is a result of the 2018 libigl hackathon at NYU. The major changes are:

• a simplified cmake set up that can build a static library, tutorials, tests, and python bindings;
• cmake now uses ExternalProject_Add to download necessary/requested dependency source code and tutorial/test data
• as a result, git clone --recursive ... is no longer required
• unit tests are now part of main repo and included in continuous integration (libigl/libigl-unit-tests is obsolete);
• tutorial data has been moved to libigl/libigl-tutorial-data;
• unit test data has been moved to libigl/libigl-tests-data;
• all dependencies previously in libigl/external have been removed or moved to repos (and added via ExternalProject_Add);
• documentation and the tutorial webpage has been moved to libigl/libigl.github.io;
• .git history of these files has been purged using bfg
• unfortunately this means that SHA hashes have changed and any external projects using libigl as a submodule will need to be refreshed to the new hashes.
• More information and instructions for troubleshooting at https://libigl.github.io/rewritten-history/.
• A legacy version with SHA hashes matching old repo is hosted at libigl/libigl-legacy.

The major upshot is that the old git clone --recursive that resulted in a 1.8GB libigl/ directory is now a git clone that results in 16.5MB, more than a 100x reduction in size.

Name changes:

Old	New
igl::components	igl::vertex_components
igl::slice_tets	igl::marching_tets

Version 1.3.2 Changes

• First version after all pull requests were merged during the libigl hackaton, and before switching from submodules to CMake external projects.

Version 1.3.1 Changes

• Last version before pull requests were merged during the libigl hackaton.
• igl::components has been renamed to igl::vertex_components.
• viewer.core.model matrix is gone (#700).

Version 1.3.0 Changes

List of changes related to this version:

• The CMake build system has been rewritten to be more modular and modern. libigl modules are now available as CMake target, e.g. igl::triangle or igl::opengl. See the libigl-example-project for an example of typical usage.

• igl/antweakbar and igl/opengl2 support has been removed from the CMake. The files are still available, but their use is discouraged.

• The viewer has been refactored and now supports multiple meshes. See related tutorial entry for more information. The viewer files are now split according to their dependencies. E.g. igl::viewer::Viewer has been renamed igl::opengl::glfw::Viewer.

• NanoGui has been replaced by ImGui, and is now available as a viewer plugin instead of #define

• Polyvector code has been moved to libdirectional (#630).

Version 1.2 Changes

This change introduces better organization of dependencies and removes some deprecated/repeated functions. The 3x3 svd code and dependent functions (including ARAP) were absorbed into the main library. Similarly, the boost dependency extra was absorbed.

External libraries as git subrepos

The core functionality of libigl (still) just depends on stl, c++11 and Eigen. There are additional optional dependencies (e.g. CGAL, embree, glfw, tetgen, triangle). Libigl functions using these are located (still) in sub-folders of the include directory (e.g. include/igl/cgal/, include/igl/embree/). Prior to version 1.2 we included copies of the code for some of these dependencies in the external/ directory. As of version 1.2, these have been replaced with git sub-repos. If you have cloned libigl before version 1.2 then you should issue

git submodule update --init --recursive

Deprecated/repeated functions

Old	New
igl::angles	igl::internal_angles
igl::get_modifiers	[deleted]
igl::nchoosek(offset,K,N,std::vector)	igl::nchoosek(Eigen,K,Eigen)
#include <igl/boost/components.h>	#include <igl/components.h>
#include <igl/boost/bfs_orient.h>	#include <igl/bfs_orient.h>
#include <igl/boost/orientable_patches.h>	#include <igl/orientable_patches.h>
#include <igl/svd3x3/arap.h>	#include <igl/arap.h>
#include <igl/svd3x3/arap_dof.h>	#include <igl/arap_dof.h>
#include <igl/svd3x3/fit_rotations.h>	#include <igl/fit_rotations.h>
#include <igl/svd3x3/polar_svd3x3.h>	#include <igl/polar_svd3x3.h>
#include <igl/svd3x3/svd3x3.h>	#include <igl/svd3x3.h>
#include <igl/svd3x3/svd3x3_avx.h>	#include <igl/svd3x3_avx.h>
#include <igl/svd3x3/svd3x3_sse.h>	#include <igl/svd3x3_sse.h>

Version 1.0 Changes

Our beta release marks our confidence that this library can be used outside of casual experimenting. To maintain order, we have made a few changes which current users should read and adapt their code accordingly.

Renamed functions

The following table lists functions which have changed name as of version 1.0.0:

Old	New
igl::add_barycenter	igl::false_barycentric_subdivision
igl::areamatrix	igl::vector_area_matrix
igl::barycentric2global	igl::barycentric_to_global
igl::boundary_faces	igl::boundary_facets
igl::boundary_vertices_sorted	igl::boundary_loop
igl::cotangent	igl::cotmatrix_entries
igl::edgetopology	igl::edge_topology
igl::gradMat	igl::grad
igl::is_manifold	igl::is_edge_manifold
igl::mexStream	igl::MexStream
igl::moveFV	igl::average_onto_vertices
igl::moveVF	igl::average_onto_faces
igl::plot_vector	igl::print_vector
igl::pos	igl::HalfEdgeIterator
igl::plane_project	igl::project_isometrically_to_plane
igl::project_points_mesh	igl::line_mesh_intersection
igl::read	igl::read_triangle_mesh
igl::removeDuplicates.cpp	igl::remove_duplicates
igl::removeUnreferenced	igl::remove_unreferenced
igl::tt	igl::triangle_triangle_adjacency
igl::vf	igl::vertex_triangle_adjacency
igl::write	igl::write_triangle_mesh
igl::manifold_patches	igl::orientable_patches
igl::selfintersect	igl::remesh_self_intersections
igl::project_mesh	igl::line_mesh_intersection
igl::triangulate	igl::polygon_mesh_to_triangle_mesh
igl::is_manifold	igl::is_edge_manifold
igl::triangle_wrapper	igl::triangulate

Miscellaneous

• To match interfaces provided by (all) other quadratic optimization libraries, igl::min_quad_with_fixed and igl::active_set now expect as input twice the quadratic coefficients matrix, i.e. the Hessian. For example, igl::min_quad_with_fixed(H,B,...) minimizes $\frac{1}{2}x^T H x+x^T B$.
• We have inverted the IGL_HEADER_ONLY macro to IGL_STATIC_LIBRARY. To compile using libigl as a header-only library, simply include headers and libigl in the header search path. To link to libigl, you must define the IGL_STATIC_LIBRARY macro at compile time and link to the libigl*.a libraries.
• Building libigl as a static library is now more organized. There is a build/ directory with Makefiles for the main library (Makefile) and each dependency (e.g. Makefile_mosek for libiglmosek.a)
• igl::polar_svd now always returns a rotation in R, never a reflection. This mirrors the behavior of igl::polar_svd3x3. Consequently the T part may have negative skews.
• We have organized the static library build
• The previous igl::grad function, which computed the per-triangle gradient of a per-vertex scalar function has been replaced. Now igl::grad computes the linear operator (previous computed using igl::gradMat). The gradient values can still be recovered by multiplying the operator against the scalar field as a vector and reshaping to have gradients per row.
• MASSMATRIX_* has become MASSMATRIX_TYPE_*
• The function igl::project_normals, which cast a line for each vertex of mesh A in the normal direction and found the closest intersection along these lines with mesh B, has been removed.