我正在尝试使用 assimp 加载网格以检测非流形和开放(边界)边缘。我正在使用从 assimp 中得到的顶点索引来建立顶点、边和面之间的关系。我有一个看起来像这样的脸类
#include "Face2.h"
Face2::Face2()
{
}
Face2::Face2(std::vector<unsigned int> indices)
{
m_indices = indices;
}
bool Face2::containsEdge(const Edge2 &edge)
{
// for(unsigned int i = 0; i < m_indices.size(); i++)
// {
// if(edge.getStartIndex() == m_indices[i]){
// for(unsigned int i = 0; i < m_indices.size(); i++)
// {
// edge.getEndIndex() == m_indices[i]
// }
// }
// }
for(unsigned int i = 0; i < m_indices.size(); i++)
{
if(edge.getStartIndex() == m_indices[i])
{
for(unsigned int j = 0; j < m_indices.size(); j++)
{
if(edge.getEndIndex() == m_indices[j]) return true;
}
}
}
return false;
}
std::vector<unsigned int> Face2::getIndices() const
{
return m_indices;
}
void Face2::setIndices(const std::vector<unsigned int> &indices)
{
m_indices = indices;
}
我的边类基本上只是一个保存边的起始索引和结束索引的数据结构。 我的网格类包含一个 std::vector of faces 和 std::vector of edges,它们像这样填充:
for(unsigned int i = 0; i < m_indices.size()-1; i+=2)
{
m_edges2.push_back(Edge2(m_indices[i], m_indices[i]));
}
for(unsigned int i = 0; i < m_indices.size()-1; i+=3)
{
std::vector<unsigned int> faceData;
faceData.push_back(m_indices[i]);
faceData.push_back(m_indices[i+1]);
faceData.push_back(m_indices[i+2]);
m_faces2.push_back(Face2(faceData));
}
我的主要功能有这段代码:
std::cout << "Number of edges2: " << m->getEdges2().size() << std::endl;
std::cout << "Number of faces2: " << m->getFaces2().size() << std::endl;
std::cout << "finished " << std::endl;
unsigned int nonManif = 0;
unsigned int boundary = 0;
for(unsigned int i = 0; i < m->getEdges2().size(); i++)
{
unsigned int edgeCount = 0;
for(unsigned int j = 0; j < m->getFaces2().size(); j++)
{
if(m->getFaces2().at(j).containsEdge(m->getEdges2().at(i)))
{
edgeCount++;
}
}
std::cout << "Edge#" << i << " occurences: " << edgeCount << std::endl;
if(edgeCount > 2) nonManif++;
else if(edgeCount < 2) boundary++;
}
std::cout << "Non-Manifold: " << nonManif << std::endl;
std::cout << "Boundary: " << boundary << std::endl;
我从中得到了正确数量的边和面。 边界边的数量与我从 meshlab 获得的相同模型的数量有很大差异。并且非流形边的数量始终为 0。
他们是我做错了什么,还是他们有更好的方法?
最佳答案
我认为这里有一个错误:
m_edges2.push_back(Edge2(m_indices[i], m_indices[i]));
我想应该是:
m_edges2.push_back(Edge2(m_indices[i], m_indices[i + 1]));
解决这个问题可能会解决您的问题
在具有迭代上限的面创建周期中还有另一个错误,这可能会导致 UB。应该是:
i < m_indices.size()-2
关于c++ - 使用 assimp 加载网格,并检测其中的边界和非流形边,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35293877/