several things Several things matter:
- sameThe vertex count must be the same.
= (v0...v19)
- The edge list hasmust have the same vertex indices to build each edge. That is, the same vertices must be connected.
= [[v0,v1],...[v10,v11],[v18,v19]]
- The polygon list must have the same verticesvertex indices to build each face. That is, each face must be formed by the polygon listsame vertices, in the same order.
= [[v14,v15,v7,v4],...[v7,v6,v18,v19]]
Basically, you can move the vertices all you like, but you can't change how they connect.
Here is an image to demonstrate a deformation: