Question of Cloud-mesh distances

[chris56tree]

Hi, I am new to CloudCompare. I am trying to compare the buildings of point cloud data (LAS) and mesh data (obj). I have already the compute cloud/mesh distance.

However, there are few questions that I cannot solve.

1) Is there a way that I can highlight the "C2M signed distance" in different color that are larger or smaller than 0.3m (in x axis) and 0.5m (in y axis)? (I want to find out the areas where both have large distance gap.
2) Is there a way that I can output the result?
3) Since I have thousands of the mesh buildings. In a long run, do you think that is possible to use "command line" to discover the errors automatically?

Many thanks.

Chris

[daniel]

1) You can't split the distance 'vector' along the 3 coordinates in Cloud/Mesh distances calculation mode. But if you are only interested in unsigned distances, you could sample points on the mesh and use Cloud/Cloud distances calculation instead. This would allow you to filter (or change the colors) of the points based on the distance along X and Y (you will get one scalar field per dimension).

2) You can either generate nice visuals (especially if you define your own color scale with the 'Color Scales Manager' - https://www.cloudcompare.org/doc/wiki/i ... es_Manager). Or you can export the cloud with its (distances) scalar fields as an ASCII file (which can take the form of a CSV file for instance).

3) At least you can sample points, compute the distances and export the result as an ASCII file in command line mode. You can also segment the points based on their distances.

[chris56tree]

Thank you for your prompt response!

I am trying to generate my own C2M signed distance colour at the Color Scales Manager. However, I am still not able to get it. I am trying to set colour range as possibly as follow.

-0.5 to 0.5: black
-1 to -0.5 and 0.5 to 1: blue
-2 to -1 and 1-2: green

Is it possible to do it?

Thank you.

[daniel]

Yes, but you have to cheat if you want a constant color:
- set -2 to green
- set -1.0001 to green
- set -1 to blue
- set -0.5001 to blue
- set -0.5 to black
- etc.