利用Python从PLY文件中提取颜色信息、索引信息、法线信息、模型的顶点坐标

class MeshPly:   
    def __init__(self,filename,color=[0.,0.,0.]):

	f = open(filename,'r')
	self.vertices=[]
	self.colors=[]
	self.indices=[]
	self.normals = []
	vertex_mode = False
	face_mode