void GLMesh::fillBuffers(const std::vector<Eigen::Vector3f>& colors)
{
vertices.resize(3*(mesh.faces.size() - mesh.boundaries.size()));
for (FaceCIter f = mesh.faces.begin(); f != mesh.faces.end(); f++) {
if (!f->isBoundary()) {
int i = 0;
int fIdx = 3*f->index;
HalfEdgeCIter h = f->he;
do {
VertexCIter v = h->vertex;
// set vertex
vertices[fIdx+i].position = v->position.cast<float>();
vertices[fIdx+i].normal = v->normal().cast<float>();
vertices[fIdx+i].color = colors[f->index];
vertices[fIdx+i].uv = v->uv.cast<float>();
i++;
h = h->next;
} while (h != f->he);
// set barycenters
vertices[fIdx+0].barycenter = Eigen::Vector3f(1.0, 0.0, 0.0);
vertices[fIdx+1].barycenter = Eigen::Vector3f(0.0, 1.0, 0.0);
vertices[fIdx+2].barycenter = Eigen::Vector3f(0.0, 0.0, 1.0);
}
}
}
void Mesh::buildAreaMatrix(Eigen::SparseMatrix<double>& A) const
{
std::vector<Eigen::Triplet<double>> ATriplet;
for (VertexCIter v = vertices.begin(); v != vertices.end(); v++) {
ATriplet.push_back(Eigen::Triplet<double>(v->index, v->index, v->dualArea()));
}
A.setFromTriplets(ATriplet.begin(), ATriplet.end());
}
void MeshBuilder::checkIsolatedVertices(const Mesh& mesh)
{
for (VertexCIter v = mesh.vertices.begin(); v != mesh.vertices.end(); v++) {
if (v->isIsolated()) {
std::cerr << "Warning: vertex " << v->index
<< " is isolated (not contained in any face)."
<< std::endl;
}
}
}
void GLMesh::fillPickBuffers()
{
int tris = (int)(mesh.faces.size() - mesh.boundaries.size());
// add faces
int i = 0;
pickVertices.resize(3*tris);
for (FaceCIter f = mesh.faces.begin(); f != mesh.faces.end(); f++) {
if (!f->isBoundary()) {
int j = 0;
Eigen::Vector3f color = elementColor(f->index);
HalfEdgeCIter h = f->he;
do {
// set vertex
pickVertices[3*i+j].position = h->vertex->position.cast<float>();
pickVertices[3*i+j].color = color;
j++;
h = h->next;
} while (h != f->he);
i++;
}
}
// add vertex faces
int verts = 0;
for (VertexCIter v = mesh.vertices.begin(); v != mesh.vertices.end(); v++) {
verts += v->degree();
if (v->isBoundary()) verts -= 1;
}
pickVertices.resize(3*(tris + verts));
for (VertexCIter v = mesh.vertices.begin(); v != mesh.vertices.end(); v++) {
Eigen::Vector3d n = 0.0015*v->normal();
Eigen::Vector3f p1 = (v->position + n).cast<float>();
Eigen::Vector3f color = elementColor(tris + v->index);
HalfEdgeCIter h = v->he;
do {
if (!h->onBoundary) {
Eigen::Vector3f p2 = (h->next->vertex->position + n).cast<float>();
Eigen::Vector3f p3 = (h->next->next->vertex->position + n).cast<float>();
pickVertices[3*i+0].position = p1;
pickVertices[3*i+1].position = p1 + 0.125*(p2 - p1);
pickVertices[3*i+2].position = p1 + 0.125*(p3 - p1);
pickVertices[3*i+0].color = pickVertices[3*i+1].color = pickVertices[3*i+2].color = color;
i++;
}
h = h->flip->next;
} while (h != v->he);
}
}
void MeshIO :: checkIsolatedVertices( const Mesh& mesh )
{
// print a warning if the mesh has any isolated vertices
int vertexIndex = 0;
for( VertexCIter v = mesh.vertices.begin();
v != mesh.vertices.end();
v ++ )
{
if( v->isIsolated() )
{
cerr << "Warning: vertex " << vertexIndex << " is isolated (not contained in any face)." << endl;
}
vertexIndex++;
}
}
void MeshIO :: checkNonManifoldVertices( const Mesh& mesh )
{
map<VertexCIter,int> nIncidentFaces;
for( FaceCIter f = mesh.faces.begin();
f != mesh.faces.end();
f ++ )
{
HalfEdgeCIter he = f->he;
do
{
nIncidentFaces[he->vertex]++;
he = he->next;
}
while( he != f->he );
}
for( FaceCIter f = mesh.boundaries.begin();
f != mesh.boundaries.end();
f ++ )
{
HalfEdgeCIter he = f->he;
do
{
nIncidentFaces[he->vertex]++;
he = he->next;
}
while( he != f->he );
}
int vertexIndex = 0;
for( VertexCIter v = mesh.vertices.begin();
v != mesh.vertices.end();
v ++ )
{
if( nIncidentFaces[v] != v->valence() )
{
cerr << "Warning: vertex " << vertexIndex << " is nonmanifold." << endl;
}
vertexIndex++;
}
}
void Viewer :: drawIsolatedVertices( void )
{
glPushAttrib( GL_ALL_ATTRIB_BITS );
glPointSize( 5 );
glHint( GL_POINT_SMOOTH_HINT, GL_NICEST );
glEnable( GL_POINT_SMOOTH );
glColor3f( 1., 0., 0. );
glBegin( GL_POINTS );
for( VertexCIter v = mesh.vertices.begin();
v != mesh.vertices.end();
v ++ )
{
if( v->isIsolated() )
{
glVertex3dv( &v->position[0] );
}
}
glEnd();
glPopAttrib();
}
void Mesh::buildLaplacian(Eigen::SparseMatrix<double>& L) const
{
std::vector<Eigen::Triplet<double>> LTriplet;
for (VertexCIter v = vertices.begin(); v != vertices.end(); v++) {
HalfEdgeCIter he = v->he;
double dualArea = v->dualArea();
double sumCoefficients = 0.0;
do {
// (cotA + cotB) / 2A
double coefficient = 0.5 * (he->cotan() + he->flip->cotan()) / dualArea;
sumCoefficients += coefficient;
LTriplet.push_back(Eigen::Triplet<double>(v->index, he->flip->vertex->index, -coefficient));
he = he->flip->next;
} while (he != v->he);
LTriplet.push_back(Eigen::Triplet<double>(v->index, v->index, sumCoefficients));
}
L.setFromTriplets(LTriplet.begin(), LTriplet.end());
}