Lines in scan

Something doesn't work and you don't know why? Ask here!
Post Reply
economycar
Posts: 7
Joined: 05 Jan 2017, 21:12

Lines in scan

Post by economycar » 06 Jan 2017, 01:27

Hi, this is a continuation of my post(s) from the hp forum...

So I a running the following:
- (1X) DMK23UX236
- computar M1214-MP2
- K132
- thinkpad x230 with onboard intel HD4000 graphics

I am getting vertical ridges, particularly on surfaces that are more directly facing the camera. I have made many adjustments, running the projector at 60hz, exposure at 1/60 and I have tried to run 1280x1020 RGB24 at 60fps. I have also tried projector at 50hz, exposure 1/50 and camera at 1920x1200 y800 at 50fps. Neither of those seem to work, I have turned off keystone auto and set it to zero. I set the scan to horizontal only although i think that the hand scan below was done with the setting on "both". I am even running the projector and/or laptop through a torroidal isolation transformer and I put ferrite beads on all of the cables. I can't really think of what else to do. I have seen some really nice scans with the same camera and similar setups, I'm just not sure what I am doing wrong. I have attached some scans, the hand is not a real hand by the way, it is from a prop or something.

Thanks,
Mike
Attachments
2017-01-05_20-09-39.png
2017-01-04_18-10-48.png

Curiousjeff
Posts: 123
Joined: 16 Nov 2016, 22:31

Re: Lines in scan

Post by Curiousjeff » 06 Jan 2017, 11:30

1) Your scan of the panel is pretty good. Don't forget that fusion will remove some surface artifacts. You can also use smooth option at the scan level.
It depends on the precision you are looking for and the purpose of the scan.
One last option is to download the trial version of Zbrush and very quickly clean your mesh with the smooth brush (or with Blender, which is free). Takes a few minutes.

2) If this is a "living" hand, then of course you will have surface artifacts due to motion/mouvement.
Solutions:

use few patterns and use a high frame rate. Try to get a scan within 3 seconds (time the pattern is being projected).

Add support for the hand to make it easier on the model.

Of course, if it is a non living hand, forget the above.

Jeff

User avatar
Micr0
Posts: 413
Joined: 15 Nov 2016, 15:20

Re: Lines in scan

Post by Micr0 » 06 Jan 2017, 15:56

Curiousjeff wrote:1) Your scan of the panel is pretty good. Don't forget that fusion will remove some surface artifacts. You can also use smooth option at the scan level.
It depends on the precision you are looking for and the purpose of the scan.
One last option is to download the trial version of Zbrush and very quickly clean your mesh with the smooth brush (or with Blender, which is free). Takes a few minutes.

2) If this is a "living" hand, then of course you will have surface artifacts due to motion/mouvement.
Solutions:

use few patterns and use a high frame rate. Try to get a scan within 3 seconds (time the pattern is being projected).

Add support for the hand to make it easier on the model.

Of course, if it is a non living hand, forget the above.

Jeff
I agree. The panel scan is not bad at all. When you scan an object you will presumably take a number of scans. David weights the accuracy of each point and when you combine your scans David takes this into account rejecting data that is more likely to be erroneous or less accurate. This often results in a smoother mesh after fusion. even with the smoothing setting at a minimum.
µ

economycar
Posts: 7
Joined: 05 Jan 2017, 21:12

Re: Lines in scan

Post by economycar » 07 Jan 2017, 16:44

Hi, I realize that the scans are decent but the line problem is still an issue. I did a test with David 4 vs David 5 using the same settings and David 4 came out with what I would consider to be superior results. I have zoomed in a bit on the David 5 image but at the same scale, the David 4 result is still better. I haven't really explored david 4 but are there any downsides to just using it instead? I have found that the david 5 license isn't recognized by david 4 which is annoying. Any thoughts? I also wanted to say thanks to everyone who has been so helpful with this stuff since HP doesn't seem to be providing much help.
Thanks,
Mike

Also, the hand isn't real. It is probably from some old animatronic display or something, I had it laying around and it seemed like a good thing to scan.
Attachments
2017-01-07_11-24-09.png
David 4
2017-01-07_11-30-29.png
David 5

SilverGhost
Posts: 11
Joined: 07 Mar 2017, 07:47

Re: Lines in scan

Post by SilverGhost » 07 Mar 2017, 08:19

Have you solved the lines problem? I got same problem and have no Idea what else I could try... The lines only appear at the surfaces facing the camera, the surfaces facing the projector are completly perfect.

User avatar
Micr0
Posts: 413
Joined: 15 Nov 2016, 15:20

Re: Lines in scan

Post by Micr0 » 07 Mar 2017, 15:10

I should have said something about the hand scans (David 4-5 comparison). Even the David 5 Scan is about as good as you could possibly ask for IMO. Again after aligning a number of scans, those lines will almost go away during fusion. FWIW I've used and tested $10k-$60 scanning systems and even then the surfaces are rarely much better than what you got with out their software doing some (sometimes a lot) processing. As for the first hand pic, I get that still sometimes. I rotate the subject a degree or two, Wait till everything settles and scan again. With HD scanning even air movement and or vibration through the floor can show up as lines/surface distortion.
µ

SilverGhost
Posts: 11
Joined: 07 Mar 2017, 07:47

Re: Lines in scan

Post by SilverGhost » 09 Mar 2017, 07:06

Here is the stator of electric motor. 20 horizontal turns after fusion.
2017-03-09_09-58-00.png
stator

User avatar
avogra
Site Admin
Posts: 102
Joined: 11 Nov 2016, 17:27
Location: Munich, Germany
Contact:

Re: Lines in scan

Post by avogra » 12 Mar 2017, 16:12

I think the topic fits better in "Troubleshooting" and moved it there.

Post Reply