scanning wioth markers

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spark
Posts: 43
Joined: 06 Mar 2017, 20:44

scanning wioth markers

Post by spark »

hi, does anybody tried scanning with markers?
i tried to use the function in flexscan3d and had a lot of trouble with marker detection.
the markers on my black rotary table i prepared are not detected...
it there a marker size that is specified and i used a wrong diameter, or what might be the problem?
I used hdr scanning on/off and different angles.
i got a improovement sticking the markers to the object, but still here only a minority of the available markers were detected.
The result after scanning is not a round marker circle. is this normal? any idea of improovements?

regards, spark
spark
Posts: 43
Joined: 06 Mar 2017, 20:44

Re: scanning wioth markers

Post by spark »

markers gives you a great opportunity to improove your workflow.
flexscan dont like them on invisible (black) background on rotary, so i left the manual rotaty table unpainted...

https://picload.org/view/dddgawaw/dsc08633.jpg.html
https://picload.org/view/dddgawai/dsc08628.jpg.html
https://picload.org/view/dddgoggr/dsc08631.jpg.html
https://picload.org/view/dddgawal/2.png.html
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Micr0
Posts: 586
Joined: 15 Nov 2016, 15:20
Location: New York City

Re: scanning wioth markers

Post by Micr0 »

I've never used stick on markers with David. I have used them with the Eva to scan featureless surface surfaces. in my understanding they would only really be useful when stuck directly the subject. The reason is the same reason I stopped using spheres (with David) they tended to fall outside of the ideal scan envelope and therefore were slightly distorted and likewise didn't help. On something like that cylinder head, I don't really see that they would help that much. They certainly wouldn't compensate for poor calibration.
µ
spark
Posts: 43
Joined: 06 Mar 2017, 20:44

Re: scanning wioth markers

Post by spark »

in case of the cylhead they are really useful, because the structure of the heatsink makes it really hard to align single scans based on surface features...
calibration ist still important for sure. i do 360deg with markers, align the scans, merge them, delete markers. move to a different angle scan, merge and align based on surface structure... otherwise you need markers on the object...
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Micr0
Posts: 586
Joined: 15 Nov 2016, 15:20
Location: New York City

Re: scanning wioth markers

Post by Micr0 »

spark wrote: 30 Dec 2017, 05:57 in case of the cylhead they are really useful, because the structure of the heatsink makes it really hard to align single scans based on surface features...
calibration ist still important for sure. i do 360deg with markers, align the scans, merge them, delete markers. move to a different angle scan, merge and align based on surface structure... otherwise you need markers on the object...
If they work for you then use them. Here is a 1929 Harley head I did a while ago:
Harley Head4.jpg
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spark
Posts: 43
Joined: 06 Mar 2017, 20:44

Re: scanning wioth markers

Post by spark »

i am impressed that you captured the heatsink structure up to the ground!
nice work! regards, spark
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