读取ply文件中的点云属性

通过open3d只能读取xyz坐标，对于ply中存储的其他点云属性字段，比如法向量、强度、颜色等等则不能很好的读取。因此参考了相关代码实现了点云属性的读取，代码如下：

import numpy as np

def read_ply(infile, limit_points=0, move_to_origin=False, read_normals=True):
	"""collect vertex coordinates and normals from input file"""
	ox,oy,oz = (0,0,0)
	datadict = {}
	with open(infile) as f:
		vertexcount = facecount = None
		property_dict = {}
		property_count = 0
		while True:
			line = f.readline()
			if line.startswith("element vertex"):
				vertexcount = line.split()[-1]
				while True:
					line = f.readline()
					prev_cursor_pos = f.tell()
					if line.startswith("property"):
						property_name = line.split()[-1]
						property_dict[property_name] = property_count
						property_count += 1
					else:
						f.seek(prev_cursor_p