我试图用从CGAL :: Surface_mesh检索的数据填充我自己的结构。
您可以通过..
将面添加到曲面网格中CGAL::SM_Face_index face = SM_Surface_Mesh.add_face(SM_Vertex_Index, SM_Vertex_Index, SM_Vertex_Index);
..但是如何在给定SM_Face_Index的情况下检索该面部?我试过筛选文档,但无济于事。
InteropMesh * outputMesh = new InteropMesh();
uint32_t num = mesh1.number_of_vertices();
outputMesh->vertexCount = num;
outputMesh->vertices = new InteropVector3[num];
for (Mesh::Vertex_index vd : mesh1.vertices())
{
uint32_t index = vd; //via size_t
Point data = mesh1.point(vd);
outputMesh->vertices[index].x = (float)data.x();
outputMesh->vertices[index].y = (float)data.y();
outputMesh->vertices[index].z = (float)data.z();
}
outputMesh->indices = new uint32_t[mesh1.number_of_faces() * 3];
for (CGAL::SM_Face_index fd : mesh1.faces())
{
//? How do I get the three vertex indices?
}
答案 0 :(得分:3)
这样获取顶点和面索引的简单方法可以完成;
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Surface_mesh<K::Point_3> Mesh;
Mesh sm;
// sm created here or as a result of some CGAL function
std::vector<float> verts;
std::vector<uint32_t> indices;
//Get vertices ...
for (Mesh::Vertex_index vi : sm.vertices()) {
K::Point_3 pt = sm.point(vi);
verts.push_back((float)pt.x());
verts.push_back((float)pt.y());
verts.push_back((float)pt.z());
}
//Get face indices ...
for (Mesh::Face_index face_index : sm.faces()) {
CGAL::Vertex_around_face_circulator<Mesh> vcirc(sm.halfedge(face_index), sm), done(vcirc);
do indices.push_back(*vcirc++); while (vcirc != done);
}
此示例假设输出三角形(即每3个索引描述一个三角形),但正如Andry指出的那样,面部可能具有更多索引。
应该添加另一个功能来检查人脸索引计数,如果索引数超过3,则将人脸分成三角形。
答案 1 :(得分:2)
Surface_mesh
数据结构不仅可以表示三角形网格。这意味着每个面可能有超过3个顶点。
获得面后,您可以在其边界上导航并获取源顶点和目标顶点。
例如,你可以这样做:
Surface_mesh::Halfedge_index hf = sm.halfedge(fi);
for(Surface_mesh::Halfedge_index hi : halfedges_around_face(hf, sm))
{
Surface_mesh::Vertex_index vi = target(hi, sm);
}
你也可以手工完成:
Surface_mesh::Halfedge_index hstart = sm.halfedge(fi), hi=hstart;
do{
Surface_mesh::Vertex_index vi = target(hi, sm);
hi=sm.next(hi);
}
while(hi!=hstart)