cut tech thread: virtual facet size

[Rhino]

Date: 12/27/2006 2:54:32 PM
Author: strmrdr

Date: 12/27/2006 1:40:49 PM
Author: JohnQuixote

Date: 12/24/2006 4:07:42 PM
Author: Garry H (Cut Nut)

Some scanner companies attepmt to use their software to ''average'' out stone defects and make their models symetrical.

There is a cheat programmed into the algos that draws a straight line between high spots in the edge detection. If you want to see further proof run a stone with an indented natural on a flat facet.

Marty, one of the reasons GIA gives for rounding is, in fact, that some non-contact devices can''t overcome this kind of limitation, along with variable repeatability.

yep thats why software updates are suspect.
they could just be guessing prettier instead of measuring better.
which it sounds like serg is saying is happening here.
running a different shape stone should help show if the fix is real.

What I don''t get though is on the OGI file (that resolves the upper halves), it''s upper half facet angles are within a half a degree of the Helium and Sarin measurements regarding those angles. Perhaps its generating 2 models? I''ll see what the reply is.

STRM!!! How the heck are ya man? Are you officially *out* and recovered?

Peace,

 

[JohnQuixote]

Date: 12/27/2006 2:54:32 PM
Author: strmrdr

Date: 12/27/2006 1:40:49 PM
Author: JohnQuixote

Date: 12/24/2006 4:07:42 PM
Author: Garry H (Cut Nut)

Some scanner companies attepmt to use their software to 'average' out stone defects and make their models symetrical.

There is a cheat programmed into the algos that draws a straight line between high spots in the edge detection. If you want to see further proof run a stone with an indented natural on a flat facet.

Marty, one of the reasons GIA gives for rounding is, in fact, that some non-contact devices can't overcome this kind of limitation, along with variable repeatability.

yep thats why software updates are suspect.
they could just be guessing prettier instead of measuring better.
which it sounds like serg is saying is happening here.
running a different shape stone should help show if the fix is real.

Helium is the leader with authenticity. Sarin's later versions are better, including their forthcoming release. It will be interesting to see if Ogi's update is more guess or measure. Rhino, have you updated since Ogi did their R&D for GIA Facetware? If not that could be an issue (?)

 

[Rhino]

Date: 12/27/2006 5:06:19 PM
Author: JohnQuixote

Date: 12/27/2006 2:54:32 PM
Author: strmrdr

Date: 12/27/2006 1:40:49 PM
Author: JohnQuixote

Date: 12/24/2006 4:07:42 PM
Author: Garry H (Cut Nut)

Some scanner companies attepmt to use their software to ''average'' out stone defects and make their models symetrical.

There is a cheat programmed into the algos that draws a straight line between high spots in the edge detection. If you want to see further proof run a stone with an indented natural on a flat facet.

Marty, one of the reasons GIA gives for rounding is, in fact, that some non-contact devices can''t overcome this kind of limitation, along with variable repeatability.

yep thats why software updates are suspect.
they could just be guessing prettier instead of measuring better.
which it sounds like serg is saying is happening here.
running a different shape stone should help show if the fix is real.

Helium is the leader with authenticity. Sarin''s later versions are better, including their forthcoming release. It will be interesting to see if Ogi''s update is more guess or measure. Rhino, have you updated since Ogi did their R&D for GIA Facetware? If not that could be an issue (?)

Hi John,

Yep. After the Symposium the OGI rep came out to my store to see that the install was correct etc. So that file was generated with my older OGI scanner but with the newer software. In the GIA scanner that OGI makes, they''re using a newer and better camera for the scans now which are high definition camera''s which were never used in the scanners previously. Howard Pomerantz of GIA has more elaborate plans for the scanner too which will include some yet to be released enhancements he was telling me about at the symposium.

The unit that''s on its way to me now has 2 Hi Def camera''s in it (being a 2 channel model) as well as the latest software release with all the bells and whistles so I''m interested to see how that will perform and more inparticular it''s ability to create models.

On the Sarin front there''s some new things on the horizon which I''m not sure I can discuss publicly but look very interesting as well.

Peace,

 

[Garry H (Cut Nut)]

Date: 12/27/2006 7:38:05 AM
Author: adamasgem

Date: 12/21/2006 9:57:29 AM
Author: adamasgem


Here are the links to the virtual facet ASET images versus tilt (5 degree increments) courtesy of Peter Yantzer of AGS Laboratory.
.
Thanks also to Leonid for uploading the large files...

The file naming conventions define the parameters..
Symmetrical..

Both have 53 Table size, 80% Lower Girdle facet length

Nominal Tolkowsky

40.75 pavilion angle 34.5 Crown


www.pricescope.com/uploads/p4075t53c345s50lg80-combine_lg.gif

40.4 pavilion angle 36.5 Crown Angle


www.pricescope.com/uploads/p404t53c365s50lg80-combined.gif





These ASET images show the regions where the virtual facet is collecting the light...

One has to realize that NO stone has ''perfect'' physical symmetry, nor can one ''really'' measure the stone, and that ANY small measurement error may propogate into a substantailly different rendering, ASET or phototreal, and by their vary nature, these analyses are qualitative...

EVEN physical devices, especially like a small Hearts and Arrows Viewer are limited, as relative size of the stone to the device (~1'' diameter in the H&A case) alters the input ray coloration (image) and that two IDENTICALLY cut stones of different sizes will present different images..

The larger the device, the smaller the contrast (color) cutoffs and the less sensitive the visual presentation is versus stone size..

One can only do the ''job'' consistently by software, and even then the limitations of the scanners come into play..

One small note for the community is that while in Israel I visited Sarin, and they have made great improvements in their scanner recognition software with regard to being able to ''accurately'' scan the EightStar and NewLine class of stones, and I believe the software upgrades will be distributed shortly.. I will be discussing some minor issues with them, and will be interested to see comparisons of the scans among various vendors on the same stone (Helium/OGI/Sarin {in alphabetical order]). More on this in a new thread..

Getting back on the original track for this thread, here is a comparable ASET images for the Tolkowsky nominal above with the pavilion rotated 22.5 degrees with respect to the crown. Again thanks to Peter Yanzter of AGS for running this simulation.

https://www.pricescope.com/uploads/tolk-primary-pav-rotated-22.gif

Marty I had in mind something more like 1 degree or less of twist - not a total mismatch 9which I have seen many times in Indian smalls and in some proportion sets they actually work quite well.

 

[Rhino]

Date: 12/22/2006 12:07:29 AM
Author: Serg

re:''''Marty, look at the meet point faceting as well.

The OGI generates .stl files also and when I attempted an import into DiamCalc, for some reason it wouldn''t let me import the file. I was able to open the .stl file with a program Pete had turned me onto called ''Solid View'' and the model appeared as it does in the first graphic I posted above.

When I saw the model here generated by the OGI and if this is reflected in the new updates coming down the pike, I thought this was an excellent improvement and I look forward to getting their updated scanner/software on this''''

Rhino,

please scan diamond with just good meet points faceting ( +-20 microns) and publish same OGI image.
There is easy to receive model with perfect meet points faceting( simple rounded). One algorithm for excellent and good symmetry, other for bad symmetry. But all good will come to excellent

Sorry for missing this Serg. I put the files together but got a little sidetracked.

Here''s a screen shot taken from the web viewer .ogi file (same that showed the 8* with excellent meet points) on a stone that''s so-so. BTW I got an email back from OGI and the discrepancy between the .stl''s and the .ogi files I am told will be alleviated in this update. Gem file based on Helium next.

 

[JohnQuixote]

 

[Regular Guy]

Date: 12/27/2006 9:59:40 AM
Author: adamasgem
Sergey.. I''m having trouble decoding the OGI binary STL file.. I used the STL standard binary structure (with the 2 byte padding at the end of each triangle) and could discern 14342 triangles [from the second record](which is rediculous), but came up with a file error when I tried to combine triangles with common normals. Any suggestions???? Is each whole triangle in a separate record??

I always have trouble with this....

...no, not really, sorry.

John, do you happen to know what is in the background of the picture behind Brian in the picture?

Hope you''re all having a happy holiday period.

 

[Rhino]

Here''s the .gem file on that same stone from the Helium.

 

[Rhino]

 

[Rhino]

Date: 12/28/2006 2:51:07 PM
Author: Regular Guy

Date: 12/27/2006 9:59:40 AM
Author: adamasgem
Sergey.. I''m having trouble decoding the OGI binary STL file.. I used the STL standard binary structure (with the 2 byte padding at the end of each triangle) and could discern 14342 triangles [from the second record](which is rediculous), but came up with a file error when I tried to combine triangles with common normals. Any suggestions???? Is each whole triangle in a separate record??

I always have trouble with this....

...no, not really, sorry.

John, do you happen to know what is in the background of the picture behind Brian in the picture?

Hope you''re all having a happy holiday period.

You too Ira!

 

[Rhino]

Marty and any interested,

If you''re reading ...

I just updated our Sarin with the latest updates. Check this out man. This is on the same 8* I showed on the previous pages. I''ll post the GA next.

 

[Rhino]

The old vs the new comparison. I'd say this is an *excellent* upgrade. A world of difference in meet point scanning when you look closely.

 

[Rhino]

Load this gem advisor file into DiamCalc and look at the mesh. I''ve never seen the Sarin produce such a model on such a difficult stone. I''ll have to write and let them know. If you want the full DiamCalc file drop me a mail and I''ll forward it to ya. I''m impressed.

 

[adamasgem]

Date: 12/30/2006 5:37:55 PM
Author: Rhino
Marty and any interested,

If you''re reading ...

I just updated our Sarin with the latest updates. Check this out man. This is on the same 8* I showed on the previous pages. I''ll post the GA next.

Took awhile, but a lot of behind the scenes prodding and some genuine cooperation from Sarin greatly improved their product..

 

[adamasgem]

Date: 12/30/2006 5:43:59 PM
Author: Rhino
The old vs the new comparison. I''d say this is an *excellent* upgrade. A world of difference in meet point scanning when you look closely.

When I was in Israel I asked Sarin to print out angles to two decimal places... no sense in artificially distorting what may be better accuracy by rounding a/k/a GIA

 

[strmrdr]

good news
cant wait to see how it does on asschers compared to helium.

 

[Serg]

Hi Rhino,
re:The old vs the new comparison. I''d say this is an *excellent* upgrade. A world of difference in meet point scanning when you look closely.


Could you publishe 3 GA files for this diamond
1) Old Sarin
2) New Sarin
3)Helium

 

[pricescope]

Hey Serg, Happy New Year there in Russia!
Garry somewhere on another side of Earth - you too!

Stalking cucumber.

 

[Serg]

Date: 12/28/2006 2:58:39 PM
Author: Rhino
Here''s the .gem file on that same stone from the Helium.

thanks Rhino. I see big difference between Helium and OGI models.
Could you publish new Sarin scan( gem file) for same stone?
please send OGI stl me too.

 

[Garry H (Cut Nut)]

Date: 12/31/2006 10:41:08 AM
Author: Pricescope
Hey Serg, Happy New Year there in Russia!
Garry somewhere on another side of Earth - you too!

Stalking cucumber.

Happy New year to everyone.

We had a greeat celebration here.
Bit slow this morning tho!