A mesh is made up of vertices, edges and faces. If the mesh is static and not going to change, we can get away with just storing the vertices and a list of faces, which index into the vertex array. This does away with edges all together and is well suited to rendering on graphics hardware.
However, if we desire to perform operations on the mesh that will change the connectivity and structure, then we need to store the information in a data structure that will allow us to quickly traverse points, edges or faces. The halfedge structure is one such structure (among many) that will give us the versatility we need.
Thsi dynamic mesh class uses a half edge data structure for fast mesh operations such as split, collapse and rotate edges. It comes with a very useful 3D vector class and also has functions for loading and saving in obj format. It is an ideal starting point for applications such as:
The package comes with a demo project, which is a fully functional 3D virtual clay sculpting tool, like MudBox or Sculptris.
The easiest way to use the DynamicMesh is as follows:
Create a new mesh:
DynamicMesh* mesh = new DynamicMesh();
Create a default object:
mesh->createTetrahedron( pos, size );
Or load one from a .obj file
mesh->loadOBJ("test.obj");
Modify the vertices (will automatically set dirty flag for any vertex):
DynamicMesh::VertexList& vertices = mesh->getVertexList();
for(DynamicMesh::VertexList::iterator i=vertices.begin(); i!=vertices.end(); ++i)
{
(*i)->modifyPosition(vertex_displacement);
}
Refine the mesh:
mesh->refineMesh(min_edge_length,max_edge_length);
This will collapse edges that are too small, split edges that are too long, and rotate faces that are too slender. It will only affect edges whose vertices are dirty.
At any point you can save the mesh to a .obj file:
mesh->saveOBJ("test.obj");
Finally, cleanup:
delete mesh;
This will delete the mesh and all the vertices and halfedges it contains.
The component is amazing, really easy to use and I would recommend it to anyone who needs such functionality.
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