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RSS > Single Point tracking not working properly

doveman	#16 16/11/2012 - 18h27 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Hmm, that turned out to be an annoying waste of time. It seems almost impossible to completely fill the plastic in with colour as it just smears around a lot and the nib scratches the ink away. I bought a pack of felt tips that won't even draw on plastic, only paper and another pack of DVD writing pens, which at least will draw on the plastic but as I say, it's almost impossible to do it properly. The resulting three layers does block most visible light but there's too many patches where it will get through. I wonder if it's possible to buy sheets of red, green and blue plastic cheaply from arts & crafts shops, as then I could just cut some squares out of those and stick them together? Otherwise I think the camera film method will be a better option.
Steph	#17 18/11/2012 - 11h13 Top
Class : Moderator Posts : 656 Registered on : 16/11/2007 Off line	Hm,...what is so complicate about that? ...and again, you do not looking for optical quality. You are only tracking dots in low resolution. I wonder if it's possible to buy sheets of red, green and blue plastic cheaply from arts & crafts shops, as then I could just cut some squares out of those and stick them together? Otherwise I think the camera film method will be a better option. Yes of course, try out other solutions if you want. You can get filter gel sheets like this for example. http://www.transformationtubes.co.uk/gels.html#prices I'm always looking for no budget solutions. Edited by Steph on 19/11/2012 at 11h15.
doveman	#18 18/11/2012 - 13h46 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Yeah, mine haven't filled in as well as yours and have more gaps. That's why I bought the bigger felt-tips as well as the DVD writing ones, as I thought they'd fill it in better but unfortunately they don't work on plastic! I've tried to touch it up with the fine-nib pens but that just seems to smear the existing ink, making more gaps though, which is frustrating! Maybe I've got the "wrong" sort of plastic sheet Yeah, those filter gels are a bit expensive. I thought there might be something cheaper designed for kids to cut up EDIT: Maybe these, although there's no picture so it's hard to tell. http://hobby.uk.com/materials/plastic/clear-coloured-sheets/red.html http://hobby.uk.com/materials/plastic/clear-coloured-sheets/blue.html http://hobby.uk.com/materials/plastic/clear-coloured-sheets/green.html Or maybe these, which are only 85p for each A4 sheet. I don't know if they'd be thick enough, although I guess it might not matter once they're stuck together and to the tube mounted to the camera. http://www.londongraphics.co.uk/products/Graphic-Supplies/Board-Card-Paper-Film/Coloured-Acetate/list/perpage/20/page/1 Edited by doveman on 18/11/2012 at 17h03.
doveman	#19 18/11/2012 - 17h21 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	I did some tests with my squares as they are anyway. With the camera Exposure and Gain on max and Threshold set to under the P in Point size, the blue film blocks the most, leaving mostly lots of false detection points (I'm not testing with a LED) but little red, whereas the red film still leaves a recognisable picture in red, with a lot of red noise round the edges, the green film leaves a red image visible in the middle and lots of false detection points but not the red noise. Combined the three do make it completely black but if I reduce the Threshold (to the left) first the false detection points start appearing and then the red noise, until at fully left it's mostly all red. I'm not sure if that means that my filters are quite good enough. I obviously don't want to glue them to the tube to test, only to find I need to set the Threshold at a point where it doesn't block properly. A side-effect of having the tube stuck on the camera is it gives it a tunnel/007 appearance with my head in the middle. This might not matter as if my head's fully visible I guess the LEDs will be as well and it might even help by blocking any interference from the sides but the tube is a lot longer than it needs to be at the moment so I might try cutting it down to see if that widens the view. I've got three pieces so I can afford to waste one!
doveman	#20 20/11/2012 - 18h51 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Well I was going to go to the Covent Garden store yesterday but didn't make it but maybe it was just as well as I went to a local crafts store today and got three sheets of coloured A4 acetate for 75p each, for a grand total of £2.25 The londongraphics.co.uk site was only 85p each but it says minimum order of 5, although I don't know if they enforce that in store or just online.
doveman	#21 21/11/2012 - 21h53 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Well the coloured acetate's worked out well. I still get red noise if I reduce the Threshold past the P in "Point size" but I guess that's probably internal/electrical noise. Anyway, I get a nice big red dot now with Gain and Exposure on full. I can't test it properly until I cut down the pipe as it's restricting the camera angle too much so that it loses tracking after turning the LED left or right not very much but it looks like it should work fine once I've done that Then onto constructing a proper 3-point clip
doveman	#22 22/12/2012 - 20h37 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	I managed to test my single point today with the filters on the cam and it seems to be working. It's not really usable though as I found I had to put the sensitivity to 1.5 to be able to look SE and SW, i.e. over my shoulders (it took me a while to discover that I needed to adjust it in Profile, as the Global adjustment even on 3 barely did anything, Profile 1.5, Global 1.0 makes much more difference) and that makes it rather oversensitive and jittery. Being a single point model, it also turns the view if I move (not turn) left or right, which may be where the jitteryness is coming in as if I move my head a small amount to either side, the view rotates a heck of a lot more than it does when I turn my head, so obviously slight rotation plus slight sideways movement adds up to move the view. I'll test again when I've got my 3-point model working as I'm sure that will be much better. I noticed the LED gets rather warm but I expect that's normal!
Steph	#23 23/12/2012 - 14h37 Top
Class : Moderator Posts : 656 Registered on : 16/11/2007 Off line	Being a single point model, it also turns the view if I move (not turn) left or right, which may be where the jitteryness is coming in as if I move my head a small amount to either side, the view rotates a heck of a lot more than it does when I turn my head, so obviously slight rotation plus slight sideways movement adds up to move the view. Jitter is a deviation from the average frame rate and the result of a bad tracking. Try to get better dots. The white crosses on the dots should not flicker when you move in any direction. I noticed the LED gets rather warm but I expect that's normal! Yes, this is normal.
doveman	#24 04/06/2013 - 21h12 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	I finally managed to build a 3-point clip today It looks a bit like this one, except I've just used some stiff cardboard and it isn't anywhere near as neat http://www.free-track.net/images/point_model_gallery/tracker_02.jpg Anyway, whilst it's working and picking up the LEDs no problem, it's moving the head in other axes to the one I'm moving, so for example when I turn my head left or right, there's about +/-300 movement on the Z axis as well which moves the head forward and backward. This is with all the Profile sliders on Sensitivity 1, Smoothing 15 and the Global sliders on Sensitivity 1, Smoothing 100. If I set the Global Z sensitivity to 0, it reduces the output to +/-10 and I can't notice the head moving forward or backward anymore but that's cheating and I think with a 3-point clip I should be able to have the Z axis work but not when I'm just turning my head shouldn't I? As for the other Axis, when I pitch my head up/down, the head yaws to the the right/left as well about +/-6. I also notice that after doing this a couple of times, it loses the center position and returning my real head to the center position leaves the avatar head looking up and to the L or R. Pitching my head up/down causes around -/+5 Roll and turning it L/R causes around -/+10 Roll. Up/Down causes around -/+30 on the Y Axis and L/R causes about the same. Up/Down causes around -/+15 on the X Axis and L/R causes about -30/+60. I'm sure I just need to adjust some settings but I'm not sure what to do so I'd be grateful for any help.
Steph	#25 05/06/2013 - 08h57 Top
Class : Moderator Posts : 656 Registered on : 16/11/2007 Off line	Check settings: - Model dimensions - Profil and curves
doveman	#26 08/06/2013 - 17h02 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Thanks for those links, they're very helpful and understanding some of FreeTrack's settings Unfortunately, it seems with my clip stuck to the side of my headphones, the LEDs don't appear to be lined up in the camera's view. This is what it looks like with my head at default position. I did some strange contortions which involved leaning diagonally back and to the right, whilst leaning my head to the left so that my ear was near to my shoulder and more or less managed to get them lined up but I'm not sure how I'll adjust my clip to get it in this position with my head at rest! I have to put the Threshold near to the right end now to get it to track, whereas yesterday it worked well near the left end. and it still tends to lose tracking when I turn my head to the right. It may be because it's sunny outside (I was testing in the evening yesterday) and I've got a window to my right (the same side as the clip) and even though the curtains are closed they're still letting a lot of light through. So maybe I'll have to get some blackout curtains, or at least something to my immediate right to block the light?
Steph	#27 09/06/2013 - 10h36 Top
Class : Moderator Posts : 656 Registered on : 16/11/2007 Off line	Hi, Get your head in the natural position in front of your screen and make sure that the middle dot of the LEDs is lined up with the cross centre in the right cam-window in Freetrack. Eventually you have to out centre the webcam to the left. Then try to adjust the mount on the headset to get the dots aligned. You do not need to look for a perfect geometric adjustment as there is some tolerance in tracking. This is ok for example: Make sure that there are always and only three white crosses in the cam window, and three green control-lamps (at the bottom on the right in Freetrack-window. Otherwise it means that Freetrack track more or less than three light dots.
doveman	#28 11/06/2013 - 01h16 Top
Class : Habitué Posts : 106 Registered on : 09/05/2012 Off line	Thanks. I tried mounting the clip at the bottom rather than in the middle to see if that would straighten it out but it didn't really help. I think I might try mounting the LEDs on my headphones in a cap-type layout as that will avoid this problem. I tested again in the evening and it was fine again so it obviously was the sunlight through the curtains that was preventing it tracking properly. I'm using the red/green/blue plastic as a normal-light filter but perhaps my PS3 Eye has an internal IR filter which is preventing it tracking the LEDs as well as it should. I note in your picture you have the threshold right down but with my cam if I do that I just get a completely red picture and the red noise and random white crosses only go away when Threshold is about under the z in Point size. This was a quick check I just did without my clip connected, so I guess it's just internal electrical noise. EDIT: Oh yeah, I found this guide to removing the IR filter from the PS3 Eye but I don't really want to be pulling it apart, knowing my track record of breaking things and not getting them back together again! http://www.maximumpc.com/article/features/build_your_own_multitouch_surface_computer?page=0,2 Edited by doveman on 11/06/2013 at 01h18.

doveman

#16 16/11/2012 - 18h27

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Hmm, that turned out to be an annoying waste of time. It seems almost impossible to completely fill the plastic in with colour as it just smears around a lot and the nib scratches the ink away. I bought a pack of felt tips that won't even draw on plastic, only paper and another pack of DVD writing pens, which at least will draw on the plastic but as I say, it's almost impossible to do it properly. The resulting three layers does block most visible light but there's too many patches where it will get through.

I wonder if it's possible to buy sheets of red, green and blue plastic cheaply from arts & crafts shops, as then I could just cut some squares out of those and stick them together? Otherwise I think the camera film method will be a better option.

Steph

#17 18/11/2012 - 11h13

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Hm,...what is so complicate about that?

...and again, you do not looking for optical quality. You are only tracking dots in low resolution.

I wonder if it's possible to buy sheets of red, green and blue plastic cheaply from arts & crafts shops, as then I could just cut some squares out of those and stick them together? Otherwise I think the camera film method will be a better option.

Yes of course, try out other solutions if you want.
You can get filter gel sheets like this for example.
http://www.transformationtubes.co.uk/gels.html#prices

I'm always looking for no budget solutions.

Edited by Steph on 19/11/2012 at 11h15.

doveman

#18 18/11/2012 - 13h46

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Yeah, mine haven't filled in as well as yours and have more gaps. That's why I bought the bigger felt-tips as well as the DVD writing ones, as I thought they'd fill it in better but unfortunately they don't work on plastic! I've tried to touch it up with the fine-nib pens but that just seems to smear the existing ink, making more gaps though, which is frustrating! Maybe I've got the "wrong" sort of plastic sheet

Yeah, those filter gels are a bit expensive. I thought there might be something cheaper designed for kids to cut up

EDIT: Maybe these, although there's no picture so it's hard to tell.

http://hobby.uk.com/materials/plastic/clear-coloured-sheets/red.html

http://hobby.uk.com/materials/plastic/clear-coloured-sheets/blue.html

http://hobby.uk.com/materials/plastic/clear-coloured-sheets/green.html

Or maybe these, which are only 85p for each A4 sheet. I don't know if they'd be thick enough, although I guess it might not matter once they're stuck together and to the tube mounted to the camera.

http://www.londongraphics.co.uk/products/Graphic-Supplies/Board-Card-Paper-Film/Coloured-Acetate/list/perpage/20/page/1

Edited by doveman on 18/11/2012 at 17h03.

doveman

#19 18/11/2012 - 17h21

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I did some tests with my squares as they are anyway. With the camera Exposure and Gain on max and Threshold set to under the P in Point size, the blue film blocks the most, leaving mostly lots of false detection points (I'm not testing with a LED) but little red, whereas the red film still leaves a recognisable picture in red, with a lot of red noise round the edges, the green film leaves a red image visible in the middle and lots of false detection points but not the red noise.

Combined the three do make it completely black but if I reduce the Threshold (to the left) first the false detection points start appearing and then the red noise, until at fully left it's mostly all red. I'm not sure if that means that my filters are quite good enough. I obviously don't want to glue them to the tube to test, only to find I need to set the Threshold at a point where it doesn't block properly.

A side-effect of having the tube stuck on the camera is it gives it a tunnel/007 appearance with my head in the middle. This might not matter as if my head's fully visible I guess the LEDs will be as well and it might even help by blocking any interference from the sides but the tube is a lot longer than it needs to be at the moment so I might try cutting it down to see if that widens the view. I've got three pieces so I can afford to waste one!

doveman

#20 20/11/2012 - 18h51

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Well I was going to go to the Covent Garden store yesterday but didn't make it but maybe it was just as well as I went to a local crafts store today and got three sheets of coloured A4 acetate for 75p each, for a grand total of £2.25

The londongraphics.co.uk site was only 85p each but it says minimum order of 5, although I don't know if they enforce that in store or just online.

doveman

#21 21/11/2012 - 21h53

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Well the coloured acetate's worked out well. I still get red noise if I reduce the Threshold past the P in "Point size" but I guess that's probably internal/electrical noise. Anyway, I get a nice big red dot now with Gain and Exposure on full.

I can't test it properly until I cut down the pipe as it's restricting the camera angle too much so that it loses tracking after turning the LED left or right not very much but it looks like it should work fine once I've done that

Then onto constructing a proper 3-point clip

doveman

#22 22/12/2012 - 20h37

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I managed to test my single point today with the filters on the cam and it seems to be working.

It's not really usable though as I found I had to put the sensitivity to 1.5 to be able to look SE and SW, i.e. over my shoulders (it took me a while to discover that I needed to adjust it in Profile, as the Global adjustment even on 3 barely did anything, Profile 1.5, Global 1.0 makes much more difference) and that makes it rather oversensitive and jittery.

Being a single point model, it also turns the view if I move (not turn) left or right, which may be where the jitteryness is coming in as if I move my head a small amount to either side, the view rotates a heck of a lot more than it does when I turn my head, so obviously slight rotation plus slight sideways movement adds up to move the view.

I'll test again when I've got my 3-point model working as I'm sure that will be much better. I noticed the LED gets rather warm but I expect that's normal!

Steph

#23 23/12/2012 - 14h37

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Being a single point model, it also turns the view if I move (not turn) left or right, which may be where the jitteryness is coming in as if I move my head a small amount to either side, the view rotates a heck of a lot more than it does when I turn my head, so obviously slight rotation plus slight sideways movement adds up to move the view.

Jitter is a deviation from the average frame rate and the result of a bad tracking. Try to get better dots. The white crosses on the dots should not flicker when you move in any direction.

I noticed the LED gets rather warm but I expect that's normal!

Yes, this is normal.

doveman

#24 04/06/2013 - 21h12

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I finally managed to build a 3-point clip today

It looks a bit like this one, except I've just used some stiff cardboard and it isn't anywhere near as neat

http://www.free-track.net/images/point_model_gallery/tracker_02.jpg

Anyway, whilst it's working and picking up the LEDs no problem, it's moving the head in other axes to the one I'm moving, so for example when I turn my head left or right, there's about +/-300 movement on the Z axis as well which moves the head forward and backward. This is with all the Profile sliders on Sensitivity 1, Smoothing 15 and the Global sliders on Sensitivity 1, Smoothing 100.

If I set the Global Z sensitivity to 0, it reduces the output to +/-10 and I can't notice the head moving forward or backward anymore but that's cheating and I think with a 3-point clip I should be able to have the Z axis work but not when I'm just turning my head shouldn't I?

As for the other Axis, when I pitch my head up/down, the head yaws to the the right/left as well about +/-6. I also notice that after doing this a couple of times, it loses the center position and returning my real head to the center position leaves the avatar head looking up and to the L or R.

Pitching my head up/down causes around -/+5 Roll and turning it L/R causes around -/+10 Roll.

Up/Down causes around -/+30 on the Y Axis and L/R causes about the same.

Up/Down causes around -/+15 on the X Axis and L/R causes about -30/+60.

I'm sure I just need to adjust some settings but I'm not sure what to do so I'd be grateful for any help.

Steph

#25 05/06/2013 - 08h57

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Check settings:
- Model dimensions
- Profil and curves

doveman

#26 08/06/2013 - 17h02

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Thanks for those links, they're very helpful and understanding some of FreeTrack's settings

Unfortunately, it seems with my clip stuck to the side of my headphones, the LEDs don't appear to be lined up in the camera's view. This is what it looks like with my head at default position.

I did some strange contortions which involved leaning diagonally back and to the right, whilst leaning my head to the left so that my ear was near to my shoulder and more or less managed to get them lined up but I'm not sure how I'll adjust my clip to get it in this position with my head at rest!

I have to put the Threshold near to the right end now to get it to track, whereas yesterday it worked well near the left end. and it still tends to lose tracking when I turn my head to the right.

It may be because it's sunny outside (I was testing in the evening yesterday) and I've got a window to my right (the same side as the clip) and even though the curtains are closed they're still letting a lot of light through. So maybe I'll have to get some blackout curtains, or at least something to my immediate right to block the light?

Steph

#27 09/06/2013 - 10h36

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Hi,

Get your head in the natural position in front of your screen and make sure that the middle dot of the LEDs is lined up with the cross centre in the right cam-window in Freetrack. Eventually you have to out centre the webcam to the left.
Then try to adjust the mount on the headset to get the dots aligned.
You do not need to look for a perfect geometric adjustment as there is some tolerance in tracking.

This is ok for example:

Make sure that there are always and only three white crosses in the cam window, and three green control-lamps (at the bottom on the right in Freetrack-window.
Otherwise it means that Freetrack track more or less than three light dots.

doveman

#28 11/06/2013 - 01h16

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Thanks. I tried mounting the clip at the bottom rather than in the middle to see if that would straighten it out but it didn't really help. I think I might try mounting the LEDs on my headphones in a cap-type layout as that will avoid this problem.

I tested again in the evening and it was fine again so it obviously was the sunlight through the curtains that was preventing it tracking properly. I'm using the red/green/blue plastic as a normal-light filter but perhaps my PS3 Eye has an internal IR filter which is preventing it tracking the LEDs as well as it should. I note in your picture you have the threshold right down but with my cam if I do that I just get a completely red picture and the red noise and random white crosses only go away when Threshold is about under the z in Point size. This was a quick check I just did without my clip connected, so I guess it's just internal electrical noise.

EDIT: Oh yeah, I found this guide to removing the IR filter from the PS3 Eye but I don't really want to be pulling it apart, knowing my track record of breaking things and not getting them back together again! http://www.maximumpc.com/article/features/build_your_own_multitouch_surface_computer?page=0,2

Edited by doveman on 11/06/2013 at 01h18.

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