我刚刚被介绍给 .ply 文件，我不明白它们是如何工作的。顶点列表中每个顶点只有 3 个值：x,y,z。但是每张脸都有 5 个值，我不知道这 5 个值是什么意思。我只需要一点解释。谢谢！
2 回答
2
This simply means that the face has 5 sides or 5 vertices and each vertex's position is specified in space by the 3 values x,y,z.
于 2014-04-27T13:09:24.607 回答
2
The above answer is not exactly right to my knowledge. The first value is the number of vertices which define the face, in your case it should be 4, as there are only 4 numbers left. The four other numbers are indices of the vertices. Like often in computer science, the index of the first vertex is 0, not 1.
Some programs though support only triangular meshes, and faces with more than 3 edges are not supported.
Furthermore, if you use a visualization program which adds light and other rendering stuff, the face 3 0 1 2 is not the same as 3 0 2 1 as the triangle has another orientation.
于 2014-07-09T08:14:23.647 回答