You use the value that has more significant digits, always use the value with more significant digits. You end up with more accurate results in the end, which will help you get the right interpolation pattern in fewer tries since you're starting off from a closer point. The universe doesn't magically change just because you did some math differently

Well the thing is, the barrier does not exactly match the width of a pixel. This is due to the fact that there is a piece of glass between the barrier and the display panel. Also you need to take into account your seated distance and possibly the IPD between your eyes in order to get the perfect parallax barrier. So its not just a matter of looking up the reported specs of the monitor.

why i can not see this attachment? "ZM-M220W_Parallax_Barrier_Pattern.png" ? any idea ?

Its there, its just really small so you can barely see it. Go to this page and just do "save page as" and it should work:

download/file.php?id=792

I finally did it I think on a 22' tv. Does this look ok to you?

Yeah, that looks pretty good. Not perfect, but even my mod wasn't perfect.

Have you tried it with any games or videos yet? How is the 3D?

Yes it works good. a bit colorful sometimes, but works. There's some ghosting though... mainly in dark scenes where u see lights and stars.

I kind of forgot about this after trying a print once and failing miserably, I was reminded of it when I found the leftover trasnparencies while cleaning, figured I'd try again.

I'm having a bit of confusion with my printer. (DeskJet D1560) It doesn't specify the physical DPI, the only option above 600x600 is maximum DPI, which says black render DPI: 1200 color input DPI: 1200 Color output DPI: 4800x1200-optimized DPI. I can't find any detailed offical documentation on the DPI because HP.

I do have another printer, a Lexmark p4350, ( http://www.amatteroffax.com/xPC_Lexmark_P4350 ) but again, I'm not sure what the physical and optimized DPI is, and with neither I have no idea how to make sure it's printing the max physical DPI without doing that "optimization" BS. I think it's 2400x1200 based on the link in the parentheses, but how do I know if 2400 is the vertical or the horizontal resolution? Another thing is, how do I get past the arbitrary margins and print edge-to-edge?

FYI, monitor I'm doing this too is 1280x768, approxomately 10 1/8 " tall, 14" wide.

Sometimes they consider each color as adding to the resolution (which is why the color dpi will be 4 times the actual black resolution). For that HP it sounds like it may be 1200dpi for black, which should be enough to do this project. The Lexmark also sounds like a 1200dpi resolution. I does 2400dpi max, but it depends which direction it goes in and which direction you need to print the barrier at. For example, if the 2400dpi is the horizontal dpi, and you want to print the barrier vertically, then you can only effectively use 1200dpi. But test it out, it sounds like one of these printers should work.

I have to play cut&paste with the sheets anyway, I might as well use the highest resolution I have available to me, I just don't know what it is. I suppose I'll just try with my HP for now, I don't actually have a black cartrige in my Lexmark right now, just a photo and a color. I suppose I shouldn't have too much of a problem, the pixels on a monitor just above 720p are a lot bigger targets than the 1980p monitors most people seem to be using.

Still wish someone around here had a wide-format printer though so I could get it with one sheet >: Alas, ( and I believe I said it before ) only place is Staples with a 600 dpi wide-format printer.

I should have picked up that wide-format printer I mentioned before from the garage sale when I had the chance, not sure why I chose to get a pizza instead.


Also, fk. I just put up the test image on the monitor I was going to convert, and it's already all messed up, it looks like like the examples of overscan on Wikipedia. Stupid VGA.... maybe I can get it pixel-perfect somehow first, or else I'm already out on this project, because I can't do it on my main monitor. ;-;

Yeah, it will work best with a digital connection (ie DVI, HDMI). With VGA there is some blurring of pixels that may ruin the effect.

May be? The absolute best I could get it is looking like an example of over/underscan, for the most part it's solid grey. D: Suppose I can attempt making a barrier for my main monitor, but I won't be able to use it much >:

Worse thing is, only one of my DVI ports actually works for digital video now. Even if I did get a second monitor... stuck with one screen in VGA. Guess I'm overdue for a hardware upgrade.

Nice quality

Seems this threads past tends to resurrect after a period of dormancy..

I've been browsing the forums for a few days and playing around with various barriers from various printers with out "wow 3d" quality success.
To sum it up I've tried the tutorial Cyber posted with various results that seemed to work much better than the java calc app Galo made (no offense but I didn't have much luck so maybe that's my fault haha).

Funny thing about it is the first two patterns I made worked the best.. as in somewhat of a 3d image (very "flat" 3d).
1st was a pattern of 12px with 12px space.
2nd was a pattern of 12px with 12px space then 13px and followed by 12px space.
(this is based off of a laptop monitor at 17.3" and 1440 x 900 resolution)
Anyways now that I'm here, asking for help, and knocking myself in the head, not getting the correct pattern, any idea's?

Onto the experiment:
What formula should be used to factor in most of the variables such as pixel width modification in Photoshop or similar, focal length from observer, distance between actual pixel cell and barrier, etc...?
Does anyone know the pattern for monitor specs ill post under this?

Display specifications for project:
pixels per inch for 17.3" lcd= 98.157
dot pitch=.2587mm (pixels per mm)
width of pixel in inchs= 0.010187760414
ppb= dot-pitch(inchs) x dpi=12.225312497

I have access to some rather expensive canon printers not sure what the dpi is but should be some where upwards of 9600x2400 dpi if not higher and the size sheets that can be printed should be good enough for maybe even a 42" (forgiving size limitations of lcd+parallax combo... also* friend works in a canon showroom with nice $50k+ price tag printing units so should do a fine job once I get the calculations perfected)

Well I don't know if I have any help that hasn't already been said in the thread. Its mostly just a trial-and-error process once you get to a certain point (since each monitor is different). But I wish you the best of luck.

Turns out my screen size was actually 17.1"... store I got it from said 17.3", anyways it worked out because it made finding a pattern much easier.

Results:
pixels per inch for 17.1" lcd= 99.31
dot pitch=0.2558 (pixels per mm)
width of pixel in inches= 0.0100709
ppb= dot-pitch(inches) x dpi= 12.08508 (why the 12px barrier almost worked)

12pixel(11 Lines) + 13PIXEL(1 Line)=132+13=145/12=12.083333333333333333333333333333

12px(22 Lines) + 13PX(2L)=264+26=290/24=12.083333333333333333333333333333
_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_
pxpxpxpxpxpxpxpxpxpxpxPXpxpxpxpxpxpxpxpxpxpxpxPX

Other examples:
550 lines and 51 lines = 12.084858569051580698835274542429
*number off by .00023*

12px(183Lines) + 13PX(17Lines)= 2196+221= 2417/200= 12.085
*Number off by 0.00008*

183/200=.915} = 1
17/200=0.085}

100=8.5 +91.5|91.5+8.5=100

Only questionable thing about this is finding a relatively even px(line amount) to work with photoshop...
and I'm gonna give Galo's java app another go around.

I never really post on forums that often just skim through, I've seen a lot of the projects you've done and this one got me excited so what the heck? I'll keep posting to maybe help out other people getting into this hack/mod, very cool stuff!
Btw. How accurate have you needed this to be to work? Curious because this 12px(183Lines) + 13PX(17Lines)= 2196+221= 2417/200= 12.085 is only off by 0.00008* yet it might be a pain to get it worked out in photoshop.. unless you have some tips to set decimal place? or if possible to add and subtract a pixel here or there in the pattern.

If I can get this to work I'll more than likely get a smaller 20-22" 1080p panel and try to position the parallax barrier between the led back light and the lcd screen itself.

Well you want there to be some space between the LCD panel and the barrier. The glass is usually enough to do this, without it you won't get a parallax effect. It needs to be in front of the monitor. Because of perspective, the barrier should actually be slightly smaller than the exact dot pitch of the monitor, since it is slightly closer to your face. The distance you sit from the monitor also effects the look of it. Its probably easier to get smaller screens working, though the principle is the same for any size. Any way, hope that helps.

I figured as much and will try to adjust calculations correctly to suit these parameters. (have some plexy glass and clamping set up to try various distances and size barriers)
On the wiki page for "parallax barrier" they have this:
The newest and most convenient design, commercial products like the Nintendo 3DS, HTC Evo 3D, and LG Optimus 3D do not have the physical parallax barrier in front of the pixels, but behind the pixels and in front of the backlight. They thus send not different images to the two eyes but different light to each. This allows the two channels of light to pass through the pixels, allowing glare over the opposite pixels giving the best image quality.

* Pros
o Clear image
o Largest viewing angle
* Cons
o More expensive for mass production
o Uses 20-25% more backlight than normal displays
Wondered if anyone's tried that with this diy barrier?

Yeah, that would be interesting but I think maybe too difficult (or dangerous) to DIY.

Possibly but I'll give it a shot in the near future and come here with results.
I tried the near pattern of a discrepancy to the .00 decimal place still not that great but hey I'm not sure what I should even expect seeing how I've only ever seen a 3ds for all of about 10min a few months back and this screen in much larger, next is .000 and .00000 accuracy to test so maybe I can offer a good idea of the e- exponent people need to use.
The pattern has a decent effect at a distance of 20-27mm and seems to not cut the resolution as much so I might try to make a frame with arduino and driver compatibility between a printer hardware and computer to motorize it (for focal length adjustment )to test on larger size screens but I still get a lot of sub-pixel miss shading/coloring not to mention the amount of interleaving required overlays on the next frame too much as the image moves.
Monday I'm gonna try to get some stuff printed with the Digital press's, and Pixima Pro units in the canon show room here in town. They output 4800 x 2400 dpi1 - 4800 x 4800 dpi1 Black so I should have good success with the best calculation variations and I'll make sure to have a lot of test sample images ready.
Btw when I'm done with this project which is a want for good glasses-less 3d screen for modeling stuff with my small cnc machine, I'm really interested in making a HMD for another project how is the immersion and 3D with some commercial/consumer products you have used cyber?

hi there,im new to this forum an want to make a parrallax barrier for iphone 4s..is there someone who already had the format so i could just download & print that out..tia & more power...

You can buy one from grilli3d, no need to print it yourself.

Also check the 3DeeSlide:
http://www.spatialview.com/product/3deeslide/

Hi guys,
I have a problem with my parallax barrier. when I put it on my monitor(lenovo 1366*768) with a interleaved black and white image(black as right image and white as left image) on it, I just see RGB patterns. If it works, I should see black when I close my left eye and white when I close my right eye, but I do not. what is the problem?! It could be about my measures? help me please.

If you are seeing vertical bands of color, that is good, you just need to adjust the measurements. Like something like this:



If you are seeing wild patterns of color, then you either have the pattern totally wrong, or your printer is not good enough.

Thinking about trying this on my asus ultrabook 13" 1080p for some 3D gaming. But it looks like iZ3D driver is dead and you can no longer activate or buy a license, and they didn't make it free so it will only work for 30 days no matter what? What about TriDef, can I purchase that instead or maybe they don't support the mode required? Also not sure where to buy the transparent film and what size and if it will fit my printer. I live in sweden so it needs to be able to ship internationally or even better if I can buy local. I have one HP Laserjet P2055d (black only) and one Deskjet F4180 (color) hoping one of those will do the job.

You can use the DDD driver in 'Sharp 3D Laptop' mode.

I got the paper on ebay, you can probably find some international sellers. Just look for "transparency film" in a size that will fix your printer.

Found the paper, now the question is whether the printer is good enough. Looking at the specs, it's

1200dpi should be enough. With 600dpi you may have problems. Make sure to use black ink only and set the printer to the high quality setting.

Just installed the trial version to confirm, when I select this mode it appears to run games at a fixed resolution of 1024x768, possible to get it running at 1920x1080 or 1280x720? Other modes such as Side-by-side, line interlaced or side-by-side indicates "Any resolution" for Preferred.

You may be right. I tested a game in windowed mode and it worked, but maybe it restricts full screen games to that 1024x768 resolution.

The stereo driver I've been working on supports vertical interleave, but unfortunately only with a handful of games. It will be released in the next week so at least you can have something to test with.

Well it seems to render fine at higher resolutions as long as the game itself is capable of running in windowed mode, just tried 1600x900 in windowed and looked as it should. I haven't done any printing just yet (waiting for the film to be delivered) but it looks to render fine, as opposed to full screen where the display sets itself to 1024x768 automatically. The main games I plan on playing supports windowed so it's alright I guess. Plus there's always my 3d vision kit for the desktop in the other room so it's no deal breaker. This is just a fun project to test and have some portable S3D gaming.

I found this on ebay, http://www.ebay.ca/itm/Glasses-free-3D- ... 518wt_1139

From the description it looks like they use plexiglass with precision slits, and recommend insulating tape to angle the barrier. I haven't seen anything else as far as commercial parallax barriers for regular screens go, is this the first? I don't imagine it would be too difficult to manufacture a frame with adjustable height for a parallax barrier insert of varying resolutions/sizes, but google be damned, this DIY and that ebay item are the only things I could find.

Nice find, industrai.

Hi cybereality

I'm hoping you could help me with a few questions.

Can you please tell me if your hack worked well with viewing 3D YouTube / local mp4 3d video files on a 2d monitor.
What viewing Mode in YouTube 3D works best?

Have you tried any of these or other possible materials available on the net:
http://lenstarlenticular.com/Single/flatbed.htm
http://www.aliexpress.com/item/Lenticul ... 44659.html
http://globalwave.heteml.jp/en/html/2_about_pic3d.html

Cheers mate
Shiraz
Id be grateful if u could add me to Skype for further discussions.
Skype: ShirazAAhmed

The hack did work on YouTube for 3D videos in their "column interleaved" mode. You can also do this with the Stereoscopic Player.

I did not experiment with lenticular lenses much. I did look into it briefly but it did not seem viable because of the difficulty of matching the dot pitch of the monitor to the LPI of the lenticular sheet. I know its possible, because I've seen videos on YouTube (I think from some Japanese guy, can't remember what the video was called). So there is a way to make it work, I just don't know much about it.

Lenticular lenses can be used slanted, so you don't need to align them with pixel columns. You need to convert 3D videos to this format though, but it's just a matter of using an AVISynth script with an image mask. I posted such a script in my 3DeeSlide review thread and a movie converted in this format on YouTube.

I have a quick question ! I'm planning to do the whole parallax barrier thing as a graduation project for my bachelors degree. If i want to convert 2D video into 3D video, what should i change ? Do i have to shift every off pixel in time, do i change color scheme ? I'm not quite sure. In other words, how does the "Column Interleaved" 3D mode of youtube work (since cyberreality said the method works with that mode) ? Thanks !


My idea is to record HD Video in real time, convert it using some sort of a software (if there is no software available i'll write one myself on MatLab) and showcase the 3d technology to an audience.

Here's a kooky idea:
What if you had a printer that could make lines the width of one subpixel. Then, you make a barrier for each subpixel with the inverse of that color subpixel. Now you have a mono-color display with 3x the horizontal pixel density, since the barrier neutralizes the colors coming from each subpixel!

I'm thinking about it specifically for the rift. Your eyes move a little relative to the display, so even though parallax isn't a huge issue, it would need to be accounted for across the FoV.

Also, I wonder if Chromatic Aberration can be abused to fake more resolution, but that's a subject for another thread.