Method write

src/serializers/GltfSerializer.cpp:178–377

}

void GltfSerializer::write(const IfcGeom::TriangulationElement* o) {
	if (o->geometry().material_ids().empty()) {
		return;
	}

	size_t current_node_index = json_["nodes"].size();
    auto current_leaf_index = current_node_index;
    json_["nodes"].emplace_back();
    node_indices_[o->product()] = current_node_index;
    node_array_.push_back(current_node_index);

	auto m = o->transformation().data()->ccomponents();

	if (o->parents().empty()) {
        roots_.push_back(current_node_index);
	}
	if (!o->parents().empty()) {
		// apply inverse of last parent -> overwrite product transform (m)
        m = o->parents().back()->transformation().data()->ccomponents().inverse() * m;

        for (auto it = o->parents().rbegin(); it != o->parents().rend(); ++it) {
            const auto jt = it + 1;
            const bool is_root = jt == o->parents().rend();

            auto kt = node_indices_.find((*it)->product());
            if (kt != node_indices_.end()) {
				// parent already processed as part of other parent sequence
                json_["nodes"][kt->second]["children"].push_back(current_node_index);
                break;
			}

            
			auto mm = (*it)->transformation().data()->ccomponents();
            if (!is_root) {
                mm = (*jt)->transformation().data()->ccomponents().inverse() * mm;
			}

			json parent_node = json::object();

			std::array<double, 16> matrix_flat;
            if (settings_.get<ifcopenshell::geometry::settings::SeparateZUpNode>().get() || settings_.get<ifcopenshell::geometry::settings::WriteGltfEcef>().get() || !is_root) {
				// y-up transform is only accounted for on root
				matrix_flat = {
					mm(0,0), mm(1,0), mm(2,0), mm(3,0),
					mm(0,1), mm(1,1), mm(2,1), mm(3,1),
					mm(0,2), mm(1,2), mm(2,2), mm(3,2),
					mm(0,3), mm(1,3), mm(2,3), mm(3,3)
				};
			} else {
				// nb: note that this contains the Y-UP transform.
				matrix_flat = {
					mm(0,0), mm(2,0), -mm(1,0), mm(3,0),
					mm(0,1), mm(2,1), -mm(1,1), mm(3,1),
					mm(0,2), mm(2,2), -mm(1,2), mm(3,2),
					mm(0,3), mm(2,3), -mm(1,3), mm(3,3)
				};
			}