void
SoftBody::updateNeighborhoods()
{
auto kdTree = KdTree(posRest);
std::vector<uint32_t> indices;
indices.reserve(Neighborhood::MAX_SIZE + 1);
auto neighbor_it = neighborhoods.begin();
auto radius_it = radii.begin();
uint32_t index = 0;
for (auto& u : posRest) {
//
// A particle's neighborhood should not include itself. However, this
// kdTree will return an index for the current particle. So increment
// the neighbor count by 1, and then remove the "self" particle when
// we're done.
//
kdTree.neighbors(posRest, u, Neighborhood::MAX_SIZE + 1, *radius_it, indices);
auto selfLocation = std::find(indices.begin(), indices.end(), index);
if (selfLocation != indices.end()) {
indices.erase(selfLocation);
}
// If we find a neighbor we didn't already have, add it with an initial
// weight of zero.
//
Neighborhood newNeighbors;
for (auto j : indices) {
if (neighbor_it->hasNeighbor(j)) {
newNeighbors.push_back(neighbor_it->findNeighbor(j));
} else {
Vector3d u_ij = posRest[j] - u;
Neighbor n(j, u_ij, 0.0);
newNeighbors.push_back(n);
}
}
*neighbor_it = newNeighbors;
++neighbor_it;
++radius_it;
++index;
}
}
void mergeNeighborhoods(Neighborhood &n1, Neighborhood &n2)
{
Neighborhood::iterator it1, it2;
bool present;
for (it2 = n2.begin(); it2 != n2.end(); it2++) {
present = false;
for (it1 = n1.begin(); it1 != n1.end(); it1++) {
if ( *it1 == *it2 ) {
present = true;
break;
}
}
if (!present) {
n1.push_back( *it2 );
}
}
}
