Op 05/03/2023 om 07:27 schreef jr:
> hi,
> 
> "Bald Eagle" <cre### [at] netscapenet> wrote:
>> ...
>> Here's a sort of uv-unwrapped render of the outer and inner surfaces, ...
> 
> wow, neat.  (what do you (collective) make of the interior?  paint?)
> 
> 
LOL. I noticed (on the models) that the inside mesh is not complete. I 
guess the vase opening was too small for the scanner.

-- 
Thomas

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Il 02/03/2023 23:41, Bald Eagle ha scritto:
> Paolo Gibellini <p.g### [at] gmailcom> wrote:
> 
>> The analysis is very thorough, are you the author of the pictures?
>>
>> Paolo
> 
> Nope.  That's Mark Qvist.   I got in touch with him through github, and he's
> supposed to get back to me sometime soon.  :)
> 
> Check this out too:
> 
> https://twitter.com/mariusderomanu3
> 

I see... a more than enthusiastic expert on ancient Egypt.
Interesting!

Paolo

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Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 05/03/2023 om 07:27 schreef jr:
> > hi,
> >
> > "Bald Eagle" <cre### [at] netscapenet> wrote:
> >> ...
> >> Here's a sort of uv-unwrapped render of the outer and inner surfaces, ...
> >
> > wow, neat.  (what do you (collective) make of the interior?  paint?)
> >
> >
> LOL. I noticed (on the models) that the inside mesh is not complete. I
> guess the vase opening was too small for the scanner.
>
> --
> Thomas

Yeah, I'm guessing that it's just a partial mesh, which is a pity.  Maybe
someone will be able to do another, more complete scan of it.

I was trying to fiddle with the locations of the key features and was tired of
working blind, so I wanted a nice easy-to-see format for the inner and outer
surfaces.

- BW

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Op 05/03/2023 om 22:18 schreef Bald Eagle:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Op 05/03/2023 om 07:27 schreef jr:
>>> hi,
>>>
>>> "Bald Eagle" <cre### [at] netscapenet> wrote:
>>>> ...
>>>> Here's a sort of uv-unwrapped render of the outer and inner surfaces, ...
>>>
>>> wow, neat.  (what do you (collective) make of the interior?  paint?)
>>>
>>>
>> LOL. I noticed (on the models) that the inside mesh is not complete. I
>> guess the vase opening was too small for the scanner.
>>
>> --
>> Thomas
> 
> Yeah, I'm guessing that it's just a partial mesh, which is a pity.  Maybe
> someone will be able to do another, more complete scan of it.
> 
> I was trying to fiddle with the locations of the key features and was tired of
> working blind, so I wanted a nice easy-to-see format for the inner and outer
> surfaces.
> 

I can try to slice it using Silo. Just to see how it looks inside...

-- 
Thomas

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Thomas de Groot <tho### [at] degrootorg> wrote:

> I can try to slice it using Silo. Just to see how it looks inside...

I don't see why not.

Ben states that they were unable to scan the interior of the vessel, due to the
limitations of the structured light scanning instrumentation.

They also play around a bit with the mesh and some primitives using Blender.

https://www.youtube.com/watch?v=SQMSGkZIfao

One very interesting point that brought up is the seemingly anomalous lack of
accuracy in the lug handle holes.   Ben points out that, given there are a large
number of examples of vessels that have no holes whatsoever, that the vase may
have been manufactured without holes, and someone (less skilled) added the holes
later.

Apparently there has been some small bit of controversy between the two main
post-metrology analysts regarding reference points, proportions, and what is
real regarding various dimensions lines and ratios.

It might be interesting to develop a parameterized vessel composed entirely of
primitives as a sort of playground, that can them be exported as a mesh for
comparison in CloudCompare, Polyworks, or other more sophisticated software.

Has anyone opened it in MeshLab to see what sorts of measurement and analysis
tools are available there?

- BW

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Op 6-3-2023 om 12:44 schreef Bald Eagle:
> Thomas de Groot <tho### [at] degrootorg> wrote:
> 
>> I can try to slice it using Silo. Just to see how it looks inside...
> 
> I don't see why not.
> 
OK. So, I started fresh from the original STL file. Silo can import it, 
but it is too heavy for the program to cut it up. I did however a couple 
of basic transformations to align the mesh to the world axis.

Answering here your question below: I could load the STL into MeshLab 
and could easily simplify the mesh and convert it too quads within 
minutes. I am not too familiar with MeshLab but I guess there are a lot 
possibilities there that can be applied. I shall investigate further.

> Ben states that they were unable to scan the interior of the vessel, due to the
> limitations of the structured light scanning instrumentation.
> 
> They also play around a bit with the mesh and some primitives using Blender.
> 
> https://www.youtube.com/watch?v=SQMSGkZIfao
> 
> One very interesting point that brought up is the seemingly anomalous lack of
> accuracy in the lug handle holes.   Ben points out that, given there are a large
> number of examples of vessels that have no holes whatsoever, that the vase may
> have been manufactured without holes, and someone (less skilled) added the holes
> later.
> 
I find this a bit strange but that may be true. The vases were made as 
funerary furniture as far as I know and perhaps - depending on your 
wealth - the objects were more or less finished? In the digs all kinds 
of (un)finished states were found.

> Apparently there has been some small bit of controversy between the two main
> post-metrology analysts regarding reference points, proportions, and what is
> real regarding various dimensions lines and ratios.
> 
> It might be interesting to develop a parameterized vessel composed entirely of
> primitives as a sort of playground, that can them be exported as a mesh for
> comparison in CloudCompare, Polyworks, or other more sophisticated software.
> 
yes.

> Has anyone opened it in MeshLab to see what sorts of measurement and analysis
> tools are available there?
> 
See above.

I attach a few screenshots from the STL in Silo. I had not fully 
realised this but the whole base has not been scanned and there is that 
mess of the inside well-visible here.

-- 
Thomas

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Attachments:
Download 'vase_stl_01.jpg' (33 KB) Download 'vase_stl_02.jpg' (47 KB) Download 'vase_stl_03.jpg' (413 KB)

Preview of image 'vase_stl_01.jpg'

Preview of image 'vase_stl_02.jpg'

Preview of image 'vase_stl_03.jpg'

"Bald Eagle" <cre### [at] netscapenet> wrote:
> Hi folks,
>
> Ben from UnchartedX has just posted the stl file from a professional
> metrological scan of a pre-dynastic rose quartz vase.
>...
> The file is 44.6 MB, and it would be great if someone could convert it to a mesh
> {} or preferably mesh2 {} object.  You could likely post it on a free
> file-hosting service for the next 30 days like I did with F. Lohmueller's
> (partial) web archive.
>
>
https://unchartedx.com/site/2023/02/19/new-video-updates-to-the-vase-scan-responses-and-the-stl-file/

Hi Bill

That's a very interesting vase.

I just wrote a little Python script using numpy and numpy-stl to
extract the 473864 unique vertices from the STL file and store them
and the corresponding face indices in arrays in a POV-Ray .inc file.
(The number of non unique vertices in the STL file is 2811429.)

Here's a rendering with triangles, cylinders and spheres made with
data from that .inc file, showing the details around one of the
handles on the vase.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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Attachments:
Download 'vasetest _ 06.jpg' (1158 KB)

Preview of image 'vasetest _ 06.jpg'

"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:

> Hi Bill
>
> That's a very interesting vase.

There's a lot of interesting items that they've discovered, and the ridiculous
level of accuracy and tight tolerances in such a hard and heterogeneous material
raises a LOT of questions.

> I just wrote a little Python script using numpy and numpy-stl to
> extract the 473864 unique vertices from the STL file and store them
> and the corresponding face indices in arrays in a POV-Ray .inc file.
> (The number of non unique vertices in the STL file is 2811429.)

Hmmm.   Very nice.
1. how large is your .inc file?
2. can you make that into a mesh2 {} ?   Will that make the file size smaller?
3. would it be possible without undue work to number (with comments) the unique
vertices and correlate the redundant vertices with the ones in actual use?
(listing them all at the end of the file in a large en-bloc comment and marking
them with the numbered vertex that they are a duplicate of)

I only bring these things up because if you did such a thing and posted that
file here on the POV-Ray forums, it might generate some new traffic and
potentially bring in some new users to discover what POV-Ray has to offer.

> Here's a rendering with triangles, cylinders and spheres made with
> data from that .inc file, showing the details around one of the
> handles on the vase.

That is certainly a LOT of triangles.

I don't know if you've looked at the article by Mark Qvist posted here:
https://unsigned.io/granite-artifact/


RTI?
https://twitter.com/mariusderomanu3

I've been curious about the vertex coordinates that Mark is using for his
diagrams, and what sorts of tools would be best suited to replicating or
obtaining a truer-to-reality analysis of the surface features.   Maybe some kind
of least-squares best fit, or some way of determining which points a line would
be "tangent" to on both the rim and lug handle.


There really are a lot of different dimensions and geometric relationships to
investigate.   I'm really hoping that they are able to obtain a complete mesh of
the vessel as well as doing some microscopic / spectroscopic analyses of the
surface to see if any residues of the work-holding fixture or tooling remain
embedded in the surface.

Thanks for taking a look and processing all those vertices.  I'm curious what
your thoughts are about the vase in general, as well as what sorts of analyses
you think might be interesting to perform, and what sorts of POV-Ray fun could
be had with it.

- BW

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So, I remembered that a very fast way to analyze the curvature of a surface is
with a "zebra line" lighting setup, and so I applied that to a vase with a
mirror finish.

Nothing amazing really popped out at me, but it does show that other than some
of the 5000 years of wear, it's a very evenly curved surface.

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Attachments:
Download 'vasecurvaturelines.png' (175 KB)

Preview of image 'vasecurvaturelines.png'

Freya Holmer, working on the same topic, discovered that industries also use a
pattern of dots to look at curvature as well, and so I gave that a go.

I might have to experiment more with scales and such to see if anything
interesting happens.

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Attachments:
Download 'vasecurvaturespots.png' (196 KB)

Preview of image 'vasecurvaturespots.png'