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Dissertation question

Posted: Fri May 02, 2014 9:45 am
by soccess
As a topic for my dissertation I am looking at whether a FARO FOCUS 3D scanner can be used to record the relative degrees of charring damage on fire damaged wooden beams. I will be burning wooden joists and then scanning them from both sides as if they were still a part of the ceiling. I would like to be able to make a colour map showing the differing amounts of deviation from the original surface and/or take slices along the beam to show the damage at any point (for comparison with caliper measurements)
I am afraid that I am a beginner with 3D scanning software and would be very grateful for any suggestions or guidance.
The ideal scale for a colour map would be 1 or 2 mm increments.
Does this sound feasible?

Re: Dissertation question

Posted: Fri May 02, 2014 4:24 pm
by daniel
You are a bit off topic here. You'll get much more interesting answers on the laser scanning forum:
http://www.laserscanningforum.com

Re: Dissertation question

Posted: Sat May 03, 2014 11:09 am
by soccess
Thank you very much for replying. I had thought I could simply make the scans and then use cloudcompare to create a colour map of distances from points on the damaged surface to a vertical plane (a primitive?) with increasing distances equating to greater mass loss/damage.
I have no difficulty in making the actual scans, my question was more along the lines of "can I do it this way?"
I will ask on the laserscanning forum for advice/opinions about the best way to make the actual scans.
Jim

Re: Dissertation question

Posted: Sun May 04, 2014 9:52 pm
by daniel
Oups it seems I read your initial post too fast (it was on my cellphone ;). Sorry about that, I'll try to find time to take a second look at it tomorrow!

Re: Dissertation question

Posted: Mon May 05, 2014 11:55 am
by daniel
So to complete my answer: technically you should be able to do what you are trying to do with CloudCompare. But I have no precise information on the Faro Focus accuracy. You also need to ensure the best accuracy as possible while registering the various scans. For all this you should definitely ask for advice on the laser scanning forum.

With laser scanners, it's generally not reliable to consider measurements taken from single points only (especially to measure very small displacements). To measurement very small deviations it's always better to use multiple measurements in consideration (in order to remove the effect of white noise). E.g. fitting a plane on them and looking of how much the plane has shifted for instance (the new qM3C2 plugin is based on this idea - see http://www.cloudcompare.org/doc/wiki/in ... PluginM3C2 - and could help you detect small deviations in a reliable way). At least one should consider the distance histogram on a local area around the point.