GeoMeshPtr GeogramMeshUtils::mesh_to_geomesh(const Mesh::Ptr mesh) {
const size_t dim = mesh->get_dim();
const size_t vertex_per_face = mesh->get_vertex_per_face();
const size_t num_vertices = mesh->get_num_vertices();
const size_t num_faces = mesh->get_num_faces();
const auto& vertices = mesh->get_vertices();
const auto& faces = mesh->get_faces();
if (vertex_per_face != 3) {
throw NotImplementedError("Converting non-triangle mesh to "
"Geogram mesh is not yet implemented");
}
auto geo_mesh = std::make_shared<GeoMesh>(dim, false);
geo_mesh->vertices.clear();
geo_mesh->vertices.create_vertices(num_vertices);
geo_mesh->facets.clear();
geo_mesh->facets.create_triangles(num_faces);
for (size_t i=0; i<num_vertices; i++) {
auto& p = geo_mesh->vertices.point(i);
for (size_t j=0; j<dim; j++) {
p[j] = vertices[i*dim+j];
}
}
for (size_t i=0; i<num_faces; i++) {
geo_mesh->facets.set_vertex(i, 0, faces[i*3]);
geo_mesh->facets.set_vertex(i, 1, faces[i*3+1]);
geo_mesh->facets.set_vertex(i, 2, faces[i*3+2]);
}
return geo_mesh;
}
CellPartition::Ptr CellPartition::create(const Mesh::Ptr& mesh) {
const MatrixFr vertices = MatrixUtils::reshape<MatrixFr>(
mesh->get_vertices(), mesh->get_num_vertices(), mesh->get_dim());
const MatrixIr faces = MatrixUtils::reshape<MatrixIr>(
mesh->get_faces(), mesh->get_num_faces(),
mesh->get_vertex_per_face());
return CellPartition::Ptr(new CellPartition(vertices, faces));
}
void copy_vertices(Mesh::Ptr mesh, std::unique_ptr<DracoMesh>& draco_mesh) {
const auto dim = mesh->get_dim();
const auto num_vertices = mesh->get_num_vertices();
draco_mesh->set_num_points(num_vertices);
draco::GeometryAttribute positions;
positions.Init(draco::GeometryAttribute::POSITION, // Attribute type
nullptr, // data buffer
dim, // number of components
draco::DT_FLOAT64, // data type
false, // normalized
sizeof(Float) * dim, // byte stride
0); // byte offset
auto pos_att_id = draco_mesh->AddAttribute(
positions, // attribute object
true, // identity mapping
num_vertices); // num attribute values
for (int i = 0; i < num_vertices; ++i) {
draco_mesh->attribute(pos_att_id)->SetAttributeValue(
draco::AttributeValueIndex(i), mesh->get_vertex(i).data());
}
}
void copy_vertex_attributes(Mesh::Ptr mesh,
std::unique_ptr<DracoMesh>& draco_mesh) {
const auto num_vertices = mesh->get_num_vertices();
const auto& attribute_names = mesh->get_attribute_names();
for (const auto& name : attribute_names) {
const auto& values = mesh->get_attribute(name);
if (values.size() % num_vertices != 0) continue;
const auto num_rows = num_vertices;
const auto num_cols = values.size() / num_vertices;
draco::GeometryAttribute attr;
if (name == "vertex_normal") {
attr.Init(draco::GeometryAttribute::NORMAL, nullptr,
num_cols, draco::DT_FLOAT64, false,
sizeof(Float) * num_cols, 0);
} else if (name == "vertex_texture") {
attr.Init(draco::GeometryAttribute::TEX_COORD, nullptr,
num_cols, draco::DT_FLOAT64, false,
sizeof(Float) * num_cols, 0);
} else if (name.substr(0, 6) == "vertex"){
attr.Init(draco::GeometryAttribute::GENERIC, nullptr,
num_cols, draco::DT_FLOAT64, false,
sizeof(Float) * num_cols, 0);
} else {
// Not a vertex attribute.
continue;
}
const auto id = draco_mesh->AddAttribute(attr, true, num_rows);
for (size_t i=0; i<num_rows; i++) {
draco_mesh->attribute(id)->SetAttributeValue(
draco::AttributeValueIndex(i), values.data() +i*num_cols);
}
std::unique_ptr<draco::AttributeMetadata> metadata =
std::make_unique<draco::AttributeMetadata>();
metadata->AddEntryString("name", name);
draco_mesh->AddAttributeMetadata(id, std::move(metadata));
}
}