Re: [MORPHMET] Help with surface scans

2019-04-24 Thread Abel Bosman
Dear Pablo,

While I am unsure about lithic artifacts (as I don't have much experience
in scanning these), I have personally succesfully used a NextEngine laser
scanner to scan human crania. As you say, while it is not possible to get a
complete scan in one go, it is usually possible to do it in two sittings.
In the first instance, you place the cranium so that it is resting on its
basicranium (more or less Frankfurt Horizontal) and complete a full 360
scan. Then, you fix the cranium in place so that its occipital bone is on
the plateau and frontal bone upwards. Then you perform the second scan.
Later down the line, you can stitch these two together quite easily using
the software that comes with the scanner (ScanStudio), or use something
like Meshlab. For this stitching, you just need to make sure that you have
homologous landmarks that you can use to tell the software which structures
should align.

Ofcourse, if you have a Breuckmann structured light scanner or similar with
a wider field of view, it will be a bit easier to scan the crania, although
you still need to do two sittings, since you are not capturing the area on
which your specimen is resting-
If it is available for you, I would advise looking into a handheld scanner,
like the Artec Spider. The newer models are super fast, easy to use, and
you scan in real time, meaning that you can quite easily turn your specimen
around, continue scanning and stitch everything together with the
accompanying software.

Note that with all of these, it will still be quite difficult to get some
of the more complex areas scanned. For example, the NextEngine sometimes
has trouble in scanning the oribital roofs, as the lasers cannot reach this
area easily. Something like the Artec has less issue with this, as you can
move the scanner around more freely (as opposed to conventional scanners,
where you move the specimen around and not the scanner). Lithic artifacts
might be easier, but their reflective surfaces (think obisidian) might give
you other issues since they can scatter the lasers projected by some of
this hardware.

Hope this helps and if you have any specific questions, please let me know.

With kind regards,
Abel

Op wo 24 apr. 2019 om 05:44 schreef Murat Maga :

> Dear Pablo,
>
>
>
> It has been a while I worked with surface scanners. When I was using a
> Konica/Minolta system (15 years ago), we will do a rotational scan (using a
> turntable), at specified interval (say every 20-30 degrees of rotation).
> Then the software will stitch them together and then we would evaluate the
> missed regions in 3D rendering, then reposition the specimen accordingly
> and capture missing portions as individual snapshots and patch the 3D
> reconstruction. So essentially it was a trial and error process.
>
>
>
> I think the quality of and the speed of the reconstruction software have
> improved tremendously (almost to the point of real-time in some cases), but
> I believe process is essentially the same. Perhaps someone with more recent
> knowledge of this technology can chime in.
>
>
>
> M
>
>
>
> *From:* Pablo Fisichella 
> *Sent:* Monday, April 22, 2019 7:29 AM
> *To:* morphmet@morphometrics.org; morphmet_modera...@morphometrics.org
> *Subject:* [MORPHMET] Help with surface scans
>
>
>
> Dear All
>
> I´m trying to obtain surface scans from human skulls and lithic artifacts
> (projectile points). I wonder how can I get the most complete possible
> scans, I mean usually is not possibly to obtain a complete scan at once. I
> know that several post-scan processing software have functions to fuse
> and/or align the different surfaces obtained and then create one surface
> but perhaps several of you have some tips to obtain the most complete
> possible surface scans.
>
> Any suggestion and advice is more than welcome
>
> All best,
>
> Pablo
>
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[MORPHMET] Using residuals from allometry

2015-11-09 Thread Abel Bosman
Dear Morphometricians

I have a quick question about allometry

I am a MSc student and I am working with three-dimensional landmark 
configurations (landmarks and semi-landmarks) gained human mandibles in R 
and I am nearing the end of my analysis. As a part of my research, I 
checked the correlation with allometry using a regression between 
Procrustes aligned shape coordinates and the log of corresponding centroid 
size, and found that it is significant (as I expected beforehand). However, 
I want to do some analyses on my data and exclude the effect of size as 
much as possible. 

Am I correct in assuming that I can use the residuals created by the 
regression (the function is "plotAllometry" from the geomorph package and 
the output is in Principal components)?

Tips and suggestions are more than welcome.

Yours faithfully
Abel Bosman

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[MORPHMET] Re: Stuck on creating new dataset

2015-07-16 Thread Abel Bosman
Thank you both for the replies.

The MeshLab suggestion was very useful, as it seems to be the perfect 
program to clean up my scans and simplify them somewhat in order to reduce 
the number of duplicate vertices and faces. So, thank you for this 
suggestion.

Morpheus seems to be working properly now, albeit still excruciatingly 
slowly. I think the problem lies with the fact that my current laptop is 
not powerful enough to handle the complexity of the data that I am using. I 
will be looking into several options of upgrading and then I will hopefully 
be able to progress my analyses.

Thanks again for the replies.

With kind regards,
Abel

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[MORPHMET] Stuck on creating new dataset

2015-07-11 Thread Abel Bosman
Dear all,

My name is Abel Bosman and I am quite new (as of 2 weeks ago) to geometric 
morphometrics, so my question might be a bit silly.

I wanted to use the program Morpheus et al. to analyze my data on human 
mandibles, obtained from a NextEngine 3D scanner. I stored this data as a .ply 
file and selected new from images and then 3D. When I select the appropriate 
file, the program seems to be stuck on creating new dataset. Is this because 
my files are too large? (15.9 MB) or am I doing something wrong?. The data that 
is supplied with the program in the 3d section of the file folder (.ply files 
on monkey skulls) seems to work properly, so I am quite sure that the program 
is working as it should.

If you have any suggestions or other tips, I would be very glad to hear them.

With kind regards,
Abel

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