void SimpleInflator::connect_end_loops() {
const size_t dim = m_wire_network->get_dim();
const Float ave_thickness = m_thickness.sum() / m_thickness.size();
const auto& edge_lengths = m_wire_network->get_attribute("edge_length");
const size_t num_edges = m_wire_network->get_num_edges();
const size_t loop_size = m_profile->size();
const MatrixIr connecting_faces = generate_faces_connecting_loops(
loop_size, dim != 2);
const size_t num_connecting_faces = connecting_faces.rows();
for (size_t i=0; i<num_edges; i++) {
Float edge_length = edge_lengths(i, 0);
const auto& end_loops = m_end_loops[i];
const size_t num_segments = std::max(1.0,
std::round(edge_length / ave_thickness));
MatrixFr pts((num_segments+1)*loop_size, dim);
for (size_t j=0; j<num_segments+1; j++) {
Float alpha = Float(j) / Float(num_segments);
pts.block(j*loop_size, 0, loop_size, dim) =
end_loops.first * (1.0 - alpha) + end_loops.second * alpha;
}
MatrixIr faces(num_connecting_faces * num_segments, 3);
for (size_t j=0; j<num_segments; j++) {
faces.block(j*num_connecting_faces, 0, num_connecting_faces, 3) =
connecting_faces.array() + j*loop_size;
}
m_vertex_list.push_back(pts);
m_face_list.push_back(faces.array() + m_num_vertex_accumulated);
m_face_source_list.push_back(int(i)*(-1)-1);
m_num_vertex_accumulated += pts.rows();
}
}
void LongEdgeRemoval::triangulate_chain(
std::vector<VectorI>& faces,
const std::vector<size_t>& chain,
size_t v0_idx, size_t v1_idx, size_t v2_idx) {
const size_t chain_size = chain.size();
auto next = [&](size_t i) { return (i+1) % chain_size; };
auto prev = [&](size_t i) { return (i+chain_size-1) % chain_size; };
auto length = [&](size_t vi, size_t vj) {
return (m_vertices.row(vi) - m_vertices.row(vj)).norm();
};
MatrixIr visited = MatrixIr::Zero(chain_size, 3);
visited(v0_idx, 0) = 1;
visited(v1_idx, 1) = 1;
visited(v2_idx, 2) = 1;
MatrixIr candidates(3, 6);
candidates << v0_idx, next(v0_idx), prev(v0_idx), 0, 0, 0,
v1_idx, next(v1_idx), prev(v1_idx), 0, 0, 0,
v2_idx, next(v2_idx), prev(v2_idx), 0, 0, 0;
MatrixFr candidate_lengths(3, 2);
const Float NOT_USED = std::numeric_limits<Float>::max();
candidate_lengths
<< length(chain[candidates(0, 1)], chain[candidates(0, 2)]),
NOT_USED,
length(chain[candidates(1, 1)], chain[candidates(1, 2)]),
NOT_USED,
length(chain[candidates(2, 1)], chain[candidates(2, 2)]),
NOT_USED;
auto index_comp = [&](size_t i, size_t j) {
// Use greater than operator so the queue is a min heap.
return candidate_lengths.row(i).minCoeff() >
candidate_lengths.row(j).minCoeff();
};
std::priority_queue<size_t, std::vector<size_t>, decltype(index_comp)>
Q(index_comp);
Q.push(0);
Q.push(1);
Q.push(2);
while (!Q.empty()) {
size_t idx = Q.top();
Q.pop();
size_t selection;
if (candidate_lengths(idx, 0) != NOT_USED &&
candidate_lengths(idx, 0) <= candidate_lengths(idx, 1)) {
selection = 0;
} else if (candidate_lengths(idx, 1) != NOT_USED &&
candidate_lengths(idx, 1) < candidate_lengths(idx, 0)){
selection = 1;
} else {
continue;
}
size_t base_v = candidates(idx, selection * 3 + 0);
size_t right_v = candidates(idx, selection * 3 + 1);
size_t left_v = candidates(idx, selection * 3 + 2);
assert(visited(base_v, idx) >= 1);
if (visited.row(base_v).sum() > 1 ||
visited(right_v, idx) > 1 ||
visited(left_v, idx) > 1) {
candidate_lengths(idx, selection) = NOT_USED;
Q.push(idx);
continue;
}
visited(right_v, idx) = 1;
visited(left_v, idx) = 1;
visited(base_v, idx) = 2;
faces.push_back(Vector3I(chain[base_v], chain[right_v], chain[left_v]));
if (visited.row(right_v).sum() == 1) {
size_t right_to_right = next(right_v);
Float edge_len = length(chain[left_v], chain[right_to_right]);
candidate_lengths(idx, 0) = edge_len;
candidates.block(idx, 0, 1, 3) =
Vector3I(right_v, right_to_right, left_v).transpose();
} else {
candidate_lengths(idx, 0) = NOT_USED;
}
if (visited.row(left_v).sum() == 1) {
size_t left_to_left = prev(left_v);
Float edge_len = length(chain[right_v], chain[left_to_left]);
candidate_lengths(idx, 1) = edge_len;
candidates.block(idx, 3, 1, 3) =
Vector3I(left_v, right_v, left_to_left).transpose();
} else {
candidate_lengths(idx, 1) = NOT_USED;
}
Q.push(idx);
}
auto visited_sum = (visited.array() > 0).rowwise().count().eval();
if ((visited_sum.array() > 1).count() == 3) {
Vector3I face;
size_t count = 0;
for (size_t i=0; i<chain_size; i++) {
if (visited_sum[i] > 1) {
assert(count < 3);
face[count] = chain[i];
count++;
}
}
faces.push_back(face);
}
}