Lecture 8: Mesh Representations and Geometry Processing (23)
somaniarushi
I'm a little bit confused about what seems to be some redundancy in the structure. Is we're storing the vertex's half-edge, then why do we need to also store the "face's" half-edge. Could they be the same, or is there any subtle distinction between the two that I seem to be missing?
seenumadhavan
I'm sure you already know this from Project 2, but just for completeness it's so if we are iterating over something other than the half edges, say the faces, we can get a half edge of the face and traverse around it to get the vertices, edges, or whatever else we might need.
melodysifry
To answer the question above, even though this may result in some redundancy of one half-edge being stored in two different places, storing the half-edge in the face is necessary in order to give us a mechanism to access and traverse the vertices / edges in a certain face. Otherwise we'd have no way of getting from a face to its vertices/edges, and only have a way to get from an edge to its face
I'm a little bit confused about what seems to be some redundancy in the structure. Is we're storing the vertex's half-edge, then why do we need to also store the "face's" half-edge. Could they be the same, or is there any subtle distinction between the two that I seem to be missing?
I'm sure you already know this from Project 2, but just for completeness it's so if we are iterating over something other than the half edges, say the faces, we can get a half edge of the face and traverse around it to get the vertices, edges, or whatever else we might need.
To answer the question above, even though this may result in some redundancy of one half-edge being stored in two different places, storing the half-edge in the face is necessary in order to give us a mechanism to access and traverse the vertices / edges in a certain face. Otherwise we'd have no way of getting from a face to its vertices/edges, and only have a way to get from an edge to its face