This project implemented a skeleton-based ARAP (As Rigid As Possible) deformation algorithm on animal 3D mesh.
"main" branch perform ARAP with bear surface mesh. For the ARAP deformation with only pseudo mesh, checkout "dev_GUI" branch.
Checkout Pinocchio for linear blending code. Checkout Pseudo Mesh for pseudo mesh generation
This project uses Eigen3 library in version 3.4.0. Mac users can also install by
brew install eigen
remember to change the Eigen3_DIR in CMakeList.txt to corresponding path.
Also, libigl is used to construct the interface. The CMake build system will automatically download libigl and its dependencies using CMake FetchContent, thus requiring no setup on your part.
Compile this project using the standard cmake routine:
mkdir build
cd build
cmake ../
make
./SKELETON_BASED_ARAP
Defines the object of a Mesh().
Eigen::MatrixXd V: vertices positions.
Eigen::MatrixXd F: faces, defined by vertices' indexes.
std::vector<std::list<int>> N: neighbours of all vertices.
Eigen::MatrixXd W: weight matrix.
Eigen::MatrixXd L: Laplacian matrix.
std::vector<ControlPoint> C: list of control points.
void computeL_W_N(): compute and store the mesh's neighbour vertices N, weight matrix W and Laplacian matrix L continually.
Eigen::MatrixXd getL_withCP() const: modify the Laplacian matrix L in accordance with control points C, and return it.
void addControlPoint(int vertexIndex): push back the selected vertex into the list of control points C. Input as vertex index.
void removeControlPoint(int vertexIndex): remove the selected vertex from the list of control points C. Input as vertex index.
Defines the object of a ControlPoint().
int vertexIndexInMesh: vertex index in the mesh.
Eigen::RowVector3d wantedVertexPosition: the position of the control point.
The core of ARAP implementation.
MatrixXd arap(const Mesh &mesh, const int &kmax, const EInitialisationType &init, int *outInterationNumber = nullptr, float *outInitialEnergy = nullptr, float *outFinalEnergy = nullptr): apply ARAP algorithm on the input mesh mesh within the given kmax loops.
Output: the updated mesh vertices
The control of interface actions.
bool isBone: toggle the visualization of the surface mesh and skeleton vertices.
std::vector<int> selection: list of selected points.
bool mouseIsPressed: record whether the mouse is currently pressed or not.
Eigen::Vector3d lastProjectedPoint: stores the last projected point by the mouse.
Eigen::Vector3d firstMoveDirection: define the movement of the point on the x, y, or z-axis.
bool moveSelectionMode: toggles the mouse movement mode into mode 0 (move the camera) and mode 1 (move the selected point).
void displaySelectedPoints(igl::opengl::glfw::Viewer &viewer, const Mesh &mesh, const Mesh &bone) const: display the selected points, control points and skeleton vertices onto the interface viewer.
void projectOnMoveDirection(igl::opengl::glfw::Viewer &viewer, Eigen::Vector3d &projectionReceiver) const: project the movement of the point on the defined axis firstMoveDirection, and stores it in projectionReceiver.
void onMousePressed(igl::opengl::glfw::Viewer &viewer, Mesh &mesh, Mesh &bone, bool isShiftPressed, Eigen::MatrixXd bone_index): selects the closest vertex on the skeleton to the mouse when the user presses the mouse.
void onMouseReleased(): toggle mouseIsPressed back to false.
bool onMouseMoved(igl::opengl::glfw::Viewer &viewer, Mesh &mesh, Mesh &bone, bool &needArap, const EInitialisationType &initialisationType): under moveSelectionMode == 1, move and update the selected point on the defined axis.
void onKeyPressed(igl::opengl::glfw::Viewer &viewer, Mesh &mesh, Mesh &bone, Mesh &surface, unsigned char key, bool isShiftPressed, bool &needArap, EInitialisationType &initType): perform actions according to the input key.
key == 'M': toggle moveSelectionMode
key == 'C': add selected point as control point with mesh.addControlPoint()
key == 'R': remove the selected point from the list of control points with mesh.removeControlPoint()
key == 'X', 'Y', 'Z': toggle movement axis
key == 'B': toggle surface mesh and skeleton vertices visibility.
The main function of the project.
bool needToPerformArap: toggle the gate to conduct ARAP deformation.
igl::opengl::glfw::Viewer viewer: initialize the interface viewer based on the libigl library.
tuple<Eigen::MatrixXd, Eigen::MatrixXi> read_pseudo_off(): read pseudo mesh as .off file.
Output: a tuple of its vertices and faces.
tuple<Eigen::MatrixXd, Eigen::MatrixXi> read_surface_off(): read surface mesh as .off file.
Output: a tuple of its vertices and faces.
tuple<Eigen::MatrixXd, Eigen::MatrixXd> get_bone(Eigen::MatrixXd V): read the matching points of the skeleton bone on its pseudo mesh.
Input: pseudo mesh vertices.
Output: a tuple of skeleton vertices and the matching table.
Eigen::MatrixXd read_attachment(): read and return the coefficients for Linear Blend Skinning from pinocchio
void performARAP(Mesh &pseudo_mesh, Mesh& bone, const EInitialisationType& initialisationType, igl::opengl::glfw::Viewer& viewer, const InterfaceManager& interfaceManager): conduct ARAP deformation on the pseudo mesh.