Just about to start using marker dots and I’m curious to understand a bit more about the ones that ship with the Revopoint POP 2.
Given the light source is in the Infrared region, how are these recognized by Revo Scan and which part(s) of the dot are used in the dot’s recognition/registration? I’ve assumed it is the sharp contrast between the black to the white that is the key. Especially as the marker dots are made of vinyl and the black would be highly absorbing ……
I see there are some users (YouTube etc) that simple buy Avery label dots (or similar) and claim that results are the same?
I haven’t done a test comparison between the original dots designed to be used with IR scanners and standard commercial label dots. Thought a better understanding would be a good starting point!
The markers sold by Revopoint are printed on a particular paper with a particular ink so that they reflect IR light as needed. Printing your own markers may or may not work (it will depend on the printer, paper and ink); you are less likely to be successful if the image isn’t sharp or if the paper and ink have similar absorption in the infrared range.
You have another option with pseudo Marker mode.
Many people are using objects (crumpled paper, dice, etc.) scattered around the object being scanned to provide enough unique patterns for Feature mode to work. This has helped me on some projects.
The center of the dot is very reflective of infrared light and oversaturates the IR sensor. The black ring around it does not reflect any IR and leaves an empty ring. You are correct that it is the high contrast between the center and the ring that is used to calculate the center point of the dot. If you try to use other materials, you will not get the full dynamic range of oversaturation and zero, so the dot may not be recognized because the software does not want to mistake normal features (with middle-range reflectivity) for dots.
Thank for these comments.
I think I will have a need to use these on certain body part scans in the future. I’m having a fair bit of success without them now but when I need to scan around an arm for example they may be necessary. The Pop 2 is certainly a great tool!
With this background, would anyone know what adhesive is used on these markers? As pointed out earlier, skin reaction to them is something I want to avoid……
1 - Are these contact allergy free?
2 - If not, is there such a thing on the market??
And thanks to all helping me to get my head around understanding IR scanners!
BTW, started using an Amazon Fire Tablet with the Revo Scan software and it seems excellent…. Software interface seem fine. Got to sort out a better file transfer system to my main desktop……
Update - can directly upload to my Google Drive via the share option within the Revo Scan app…. Very simple.
You can use any markers from the market available to 0.8mm in diameter , the original markers that came with POP are not that high end , I prefer reflective markers as they works better on the angles reflecting IR light . Any markers you get online will works .
If you use markers on black surfaces , simple dots labels will works . As all you need is a dot .
You can even paint a black circle on a white tape and will works .The best is when the white surface is slightly shiny.
Marker mode is for visual tracking , there is nothing else to it , the software using the points for tracking features if the object has none.
To better tracking your arms , you can use medical tape , they are less irritating in general .
Even if you stick just a clean tape it will helps already in tracking .