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Title: I made 3D distance measurement application Post by: visusee on May 07, 2009, 04:26:54 PM I had used 2 Wii controllers to get 3D information. So far Wiimote people notice that the focal distance of Wii is "1320" without any specific reason. However, after I did several experiments, I found that it is not so true. To get focal distance, translation, rotation, principle point information, you need to calibrate your Wii controller. I have 4 Wii controllers and every controllers has a little bit different characteristics.
Anyway, now I can get 3D point information less than 1mm error when I moved 1 inch. I hope you enjoy this movie. http://www.youtube.com/watch?v=sj2-BR0PbRA Jinho Title: Re: I made 3D distance measurement application Post by: steve6 on May 12, 2009, 11:36:39 AM Hi Jinho
I have made some similar test but using my system at 6-DOF create with Wiimote: http://sanna.polito.it/wiitracking/index.htm But in my system I use a passive marker. I try to create a cloud point of a plane or sphere. What are you going to do the your cloud point??What information about precision do you have?? Thanks Steve Title: Re: I made 3D distance measurement application Post by: visusee on May 15, 2009, 01:22:11 PM Hey, steve
I am going to generate 3D object by using point cloud. (not exactly! because I will change my program to generate surface instead of points) So far I got 0.8mm ~ 0.1mm precision when I measured within small boundary. (70cm * 70cm * 70cm area) But I am sure I can get much better precision. (When I measured sensitivity of Wii, I found that Wii can sense 50 micro-meter difference, which is great) Title: Re: I made 3D distance measurement application Post by: Misha on June 01, 2009, 08:10:42 AM Good work. :) This is a thing I am getting around too. I actually believe Wii Remotes can be auto calibrated, which gets to be worked out, so that no fixed nesting (like it is done on the vid: in a wooden element) is needed.
Just for the record, here is a bit about my tries to get the Wii Remotes auto calibrated: http://www.wiimoteproject.com/project-ideas/two-wii-remote-cameras-auto-calibration/msg9863/#msg9863 Title: Re: I made 3D distance measurement application Post by: jisujiloo on July 22, 2009, 06:50:10 AM Hi!!! Jinho..
I have a question concerning using matlab for calibration. I think that the matlab uses the image files for calibration. but the wiimote gets ir dot points. how do you use matlab for calibration without image files? thanks... Title: Re: I made 3D distance measurement application Post by: Misha on July 22, 2009, 10:50:08 PM I guess there is a way to create the needed images from the point data, even if you use an external program for that. Even a PHP script would do fine.
On the other side, it is hard for me to believe that images and only images are the only input possible, since Matlab most likely extracts the point info from them in the process. Perhaps you can pass the phase of generating / procssing image data. Title: Re: I made 3D distance measurement application Post by: jisujiloo on July 30, 2009, 03:15:53 AM Hi~
I made the image to use matlab calibration tool... so I executed matlab calibration... I got the focal length... but I think that the focal length which I got is inaccurate... The focal length that I got is roughly 1080. but We usually used the focal length "1320". The number of both the focal length is very different... so I have a question concerning the number of focal length that you got... ??? thanks... |