PLY文件格式

PLY（Polygon File Format）多边形文件格式(斯坦福三角格式)，表示3D文件格式，用于存储描述为多边形集合的图形对象

PLY文件格式有

　　ASCII：用于轻松启动

　　二进制格式：用于紧凑存储和快速保存和加载

 PLY文件的结构

  Header
  Vertex List
  Face List
  (lists of other elements)

eg:

ply
format ascii 1.0           { ascii/binary, format version number }
comment this file is a cube
element vertex 8           { define "vertex" element, 8 of them in file }
property float x           { vertex contains float "x" coordinate }
property float y           { y coordinate is also a vertex property }
property float z           { z coordinate, too }
element face 6             { there are 6 "face" elements in the file }
property list uchar int vertex_index { "vertex_indices" is a list of ints }
end_header                 { delimits the end of the header }
0 0 0                      { start of vertex list }
0 0 1
0 1 1
0 1 0
1 0 0
1 0 1
1 1 1
1 1 0
4 0 1 2 3                  { start of face list }
4 7 6 5 4
4 0 4 5 1
4 1 5 6 2
4 2 6 7 3
4 3 7 4 0

说明：

注解 {……}

元素描述

element   <元素名>   <在文件里的个数> 
property   <数据类型>   <属性名-1> 
property   <数据类型>   <属性名-2> 
……

属性的数据类型

 #Name |  #Type                   | #Number of Bytes 
char   |  character               |     1                       
uchar  |  unsigned character      |     1                         
short  |  short integer           |     2                         
ushort |  unsigned short integer  |     2                         
int    |  Integer                 |     4                       
uint   |  unsigned Integer        |     4                         
float  |  single-precision float  |     4                         
double |  double precision float  |     8       

 http://paulbourke.net/dataformats/ply/