PLY file format - what is the correct header for the point cloud with color RGB info?

Question

I'm trying to export a point cloud and am running into an issue where my files are not being accepted by 3rd party tools.

I can not find a concrete example of a valid PLY point cloud file with color data embedded (I only saw binary files with color data). I pieced this together from different sources, but when I export a file with this header, I can not display it on a Mac, or view it in a web based viewer

• Can an ascii PLY file have 1 million or more points?
• Can a valid PLY file have 0 faces?
• Is the definition property list uchar int vertex_indices required?
• Is float a correct definition, or does it need to be specified like float32?
• Do I need a newline \n or both \r\n at the end of each line?

my header:

ply
format ascii 1.0
element vertex \(vertexCount)
property float x
property float y
property float z
property uchar red
property uchar green
property uchar blue
property uchar alpha
element face 0
property list uchar int vertex_indices
end_header
0.391046 0.00335238 -1.0231568 114 110 94 255
0.39227518 0.0033548833 -1.0226241 114 111 93 255
// no faces

Web based viewer does load files like these (but I do not see those type definitions in these docs: http://paulbourke.net/dataformats/ply/ :

ply
format ascii 1.0
element vertex 2
property float32 x
property float32 y
property float32 z
element face 13594
property list uint8 int32 vertex_indices
end_header
1.13927 0.985002 0.534429 
1.11738 0.998603 0.513986 
3 0 1 2 
3 0 2 3 
//...
3 6539 6367 6736 
3 6539 6736 6905 

Answer 1

This format was accepted by the point cloud library PLY reader:

ply
format ascii 1.0
element vertex \(vertexCount)
property float x
property float y
property float z
property uint8 red
property uint8 green
property uint8 blue
end_header
-0.089456566 0.21365404 -0.7840536 81 51 19
-0.0884854 0.21366915 -0.7838928 82 52 20