Average point spacing

Feel free to ask any question here
Post Reply
jco
Posts: 1
Joined: Thu Dec 05, 2013 9:45 pm

Average point spacing

Post by jco »

Hi
Does anyone know if there is a tool in CC to calculate the average distance between points within a single point cloud (not the distances between points from 2 point clouds)? This would be a really useful value to know for a point cloud. I've searched the documentation and forum but can't find anything that fits this description.
Thanks!
daniel
Site Admin
Posts: 7710
Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
Contact:

Re: Average point spacing

Post by daniel »

In fact, the actual version of the "Tools > Other > Density" is doing something approaching.

It computes for each point a cloud the distance to its nearest neighbor in the same cloud (let's call it 'radius'). Then it outputs the 'density' as d = 1 / Volume(sphere(radius)) = 1 / (4/3×π×radius^3).

So you don't get exactly what your looking for but something related (= constant / radius^3).

Not sure it helps ;)

P.S. : this tool is going to change (the user will have to give its own fixed radius as a parameter and CC will compute the actual density inside the corresponding sphere around each point. But if you think it's usefull we can recycle the old code so as to output exactly what you are looking for (i.e. simply the distance to the nearest neighbor).
Daniel, CloudCompare admin
daniel
Site Admin
Posts: 7710
Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
Contact:

Re: Average point spacing

Post by daniel »

For the records, the next official version (2.5.3, coming out soon) will the distance to the nearest neighbor in place of the old 'density' value (Tools > Other > Density > Approximate (dist. to nearest neighbor)).
Daniel, CloudCompare admin
Post Reply