Previous | Next --- Slide 23 of 36
Back to Lecture Thumbnails
yee

To visit all neighbors of a vertex, are we supposed to choose the halfedge that is not the boundary? Or I think we can't find it's twin edge.

buzz

I find this to be a really cool and convenient way to computationally describe meshes.

Max

@yee for consistency we can assume a boundary halfedge still has a twin - it's just that the twin is part of a face that is marked as a boundary. In our implementation the vertex will point to its first non-boundary halfedge, so you can still just iterate around until you get to a boundary halfedge /face.

Lockbrains

Not exactly sure why there's not a standard rule about which halfedge should the face/edge/vertices recognize, because this seems to make writing code easy to get buggy...

keliu

Does halfedge polygons has a winding order? e.g. If the halfedges are linked counter-clockwise, it means the "front" of the face.

weiyuc

This is indeed a good data structure to connect vertices, edges and faces with half-edges. We only need to consider the connection between halfedges.

KrystalTea

What data structure can we use if it's not manifold?