Question about volume and linear measurements (TOTAL NEWBIE)

[zellyen]

Hello all,

I am not an engineer nor am I technically savvy. I am a dentist under specialty training. Due to the advent of digital dentistry, my director wants me to look into a few things on the digital side. After hours of looking, I wandered upon CloudCompare. I don't know if it is capable of doing what I require, but if someone can shed some light and point me in the right direction, that would be fantastic and greatly appreciated.

1. Is there a way to calculate the linear differences between two similar meshes
- For example, after I align scan A and scan B of the SAME patient's mouth, I want to see if there are any slight discrepancies in the alignment
- I believe Hausdorff's distance can provide something similar to what I am looking for?
- I believe CloudCompare can align quite accurately and can display discrepancies in a colored map, but how do I interpret the numerical readings?

2. Is there a way to calculate the volumetric differences between two similar meshes
- For example, scan A has a pristine tooth, scan B has the same tooth that's cut down for a crown. Aligning the two meshes should be fine using other landmarks, however, is there a way to see how much (volumetrically) tooth structure is lost during the process?

Thanks in advance
Sincerely,

A dentist

[daniel]

1. Yes, indeed, you can use the 'Cloud to mesh' distance tool to compute the deviations between both meshes (well between the vertices of the compared mesh, and the surface of the reference mesh). See http://www.cloudcompare.org/doc/wiki/in ... omputation for more information.

Once you get the distances, you can show the histogram, get the average and standard deviation of the distances, and of course the maximum value, etc.

2. If you can reduce your problem to a 2.5D problem (e.g. looking to the mandibule from the top) then you can use the 'Tools > Volume > Compute 2.5D Volume' tool. However it's a bit approximate, so you'd better get a high resolution scan if you want to work on a single tooth. See http://www.cloudcompare.org/doc/wiki/in ... .5D_Volume.