[REQ] 3D Helmet using mini projectors

[smoothy]

I already have a yahoo email account and had to join the group before I can see these pics you posted. I am currently on pending. Can you not embed some of the pics on this thread so everyone can see it if say they don't have a yahoo account? Many thanks

[WebDext]

It seems everyone think that polarization is required for a projector based HMD? I don't see why this would be the case, you don't need to project different images in the same location.

The easiest / lightest solution IMO would be to project one image on a plane in front of both eyes, a simple optical divider and some lenses to extend the image plane into the distance would be fine I think.

Think about how the old school hand held stereoscopic viewers work.

It will cut the horizontal resolution of the projector in half of course, but it's a cheap solution.

Jack

[staticbuddha]

I >....

Picture 2 uses only one mini projector, with a side by side image and a spillter to stop each eye seeing the other image

[sharky]

i think this wouldn't work. HMD work only because tehy have the lense wich mmakes the screen appear far away. with this setup you would need to ahve your eyes focussing very very near and you would get headaches very quickly. IMHO i think that you need to find lenses or simple glasses to put on.

[Likay]

Just inserting another comment: It's also about the fov in X-way. Unless the image is projected VERY close to the eyes you will have problem with this. What i mean is that the right eye image starts where nose's center is and maybe it's desireable the the left eye would see more to the right.

[smoothy]

You guys are quite technically minded in this thread and seem to really know what your talking about. I have a thread here pretty much trying to do what you guys are trying to achieve. But would really like input. Please read up on the whole thread it's a very interesting prospect. And please give me your technical experience, help opinion etc, many thanks in advance

http://www.mtbs3d.com/phpBB/viewtopic.php?f=26&t=2643" onclick="window.open(this.href);return false;

[nubie]

i think this wouldn't work. HMD work only because tehy have the lense wich mmakes the screen appear far away. with this setup you would need to ahve your eyes focussing very very near and you would get headaches very quickly. IMHO i think that you need to find lenses or simple glasses to put on.

You can use any of these viewers to fix the convergence (that way both eyes are pointed straight ahead.) http://www.berezin.com/3d/viewers1.htm" onclick="window.open(this.href);return false;

I don't know about making the image appear to be farther away, maybe there are some inexpensive optics to do that.

As far as I am concerned you can make 3D with dual LCD or mini projection very easily now with the drivers from iZ3D, they support a Left/Right view on a single screen.

The trick would be to get a very small 1920x1080 projector or LCD and run it letter-boxed at 960x720 (or full 960x1080 per eye if you like that sort of thing, or use it for a desktop.)

I am sure you can get a mode in the display chip to "double" the output so that everything is just displayed twice (write the horizontal line into the buffer twice), or perhaps fiddling on the PC side with drivers would do it.

Or to be really hoky you could make the prisms and shield swing out of the way and have full HD 1080p when you aren't watching S3D.


A home user could knock one of these together for under $1000, maybe less than $500 if you find some good salvage deals. I of course would mount it on a motorcycle helmet, and look like a total dork (I am sure the 3D would be entirely worth it though ). I wonder why the tech doesn't take off? Maybe it is too hard for end users to properly set up a HMD, or it is too bulky, expensive or "uncool".

[smoothy]

Many thanks for your input, very helpful information you provide. I would like to see more people contributing to this project as I really believe we could design an HMD that's so spectacular and affordable.

[nubie]

Sorry I have nothing but imagination and construction skill, no money at all. (although with a couple bucks and a suitable helmet I could probably knock this together )




I have a 15" LCD and a couple 17" LCD's, whether or not I can get them to live on my head is another matter, and then you need to affix mirrors on long arms, best would be aluminum or fiberglass for weight, but some light and strong wood like balsa might be ok too, with aluminum mounts for the LCD and helmet.

For that matter I am sure cardboard would work if cut and attached properly, but first the basic geometry needs working out.

[nubie]

Just brainstorming this and realized that it would probably be best to mount the prisms to the helmet to keep everything lined up. It is important that the whole structure is rigid so that the path from the LCD to the Prisms doesn't move. If the helmet moves relative to your head that should be OK as both eyes should move equally and cause no strain (must test this).


Options for improvements:

If iZ3D can make a mirrored output we can have only one mirror, making it smaller (picture coming) Or if the software of the LCD panel can perform a mirroring (a third option is to remove the LCD from the backlight and flip it over)

If a suitable 1920x1080p panel is sourced in a 15" or smaller size the whole thing can be lighter/smaller and retain 960x720 (4:3) - 960x1080p (good for helicopter sims?) resolution . I know that Lumenlab.com has some of these panels in the trading/marketplace area for use in "diy projector building", but for an HMD they would be great.


One thing to be aware of is this assuredly needs support from driver makers, iZ3D is OK, but is currently the only source of drivers to make this work with one panel, which is key to keeping costs down.

Edit: Possible benefits are :

1. No ghosting, and no chance of ghosting (each eye has a completely separate light path)
2. Head tracking will be phenomenal, as you can adjust it til it accurately portrays your actions.
3. You can use this for computing by removing the prisms, probably flip to the side.

[nubie]

Here is the alternate idea:

It is necessary to mirror the LCD either in software (this probably isn't available for the OS) or in hardware/firmware.



I have seen a picture of a really old commercial HMD that works like this (think $15,000+ in the 1990s).

[kekewons]

This idea has real potential, nubie.

Much easier to follow you now that I've seen a diagram, btw (chat was moving fast last night, and I was only dimly aware of what lay behind your idea).

Siimlar, but alternative idea to your first diagram, and similar to your second: a "half HMD." Instead of mounting the monitor on the helmet, mount it (facing roughly downward) on a rig just above the head and mirror (bear with me)...on a real-time pivoting mount which would "follow" in real-time the movements of the head. Linked by something like TrackIR or a DIY headtracking solution, etc.

Primary advantage: Much less weight added to the helmet+mirror/screen unit, and much less physical strain on the neck over prolonged periods of time. You'd need only a small counterbalancing weight at the back of the helmet to offset that of the front mirror this way.

As I mentioned, I've been figuring on using some sort of motorized/headtrack mount too for the dome projection idea, but this might just be simpler still. And do-able relatively quickly and inexpensively too.


k

[nubie]

I keep coming back to the idea of a counterweight for the whole helmet:



You don't bear the weight, but the mass still remains and could cause a neck issue if you plan to use head tracking.

As I mentioned (sorry no links yet) there is a 15.4" 1080p LCD panel (1920x1200?) on Lumenlab, I don't think the weight would be very great on that. I would expect to cut the helmet down to just what is necessary for support of the display to further reduce weight, or make your own "helmet" with fiberglass.

The theory for this is the same as a pico-projector (replace mirror with a screen), but as far as I know there aren't any HD pico-projectors yet, and they don't cost under $200 apiece like a simple LCD does.

I don't quite understand you when you say:

Siimlar, but alternative idea to your first diagram, and similar to your second: a "half HMD." Instead of mounting the monitor on the helmet, mount it (facing roughly downward) on a rig just above the head and mirror (bear with me)...on a real-time pivoting mount which would "follow" in real-time the movements of the head. Linked by something like TrackIR or a DIY headtracking solution, etc.

The mirror and prism must be connected solidly to the LCD for this to work, I think you would get very sick indeed if you intend to link them with software and a remote motion system (assuming you don't go broke or get discouraged building it.)

[Okta]

I will pretend i havent seen that.

[smoothy]

Siimlar, but alternative idea to your first diagram, and similar to your second: a "half HMD." Instead of mounting the monitor on the helmet, mount it (facing roughly downward) on a rig just above the head and mirror (bear with me)...on a real-time pivoting mount which would "follow" in real-time the movements of the head. Linked by something like TrackIR or a DIY headtracking solution, etc.

I had always thought about this for an HMD. It wouldn't work for fps (first person shooters) games as when you move around with head tracking say in a 360 degrees manner it would be difficult for the tracking and rig to keep up and run smoothly. You would probably have all sorts of weight problems. But for games where your looking mainly forwards with small head movements like in racing or flight sims this rig idea could work very well.

Sorry I have nothing but imagination and construction skill, no money at all. (although with a couple bucks and a suitable helmet I could probably knock this together )




I have a 15" LCD and a couple 17" LCD's, whether or not I can get them to live on my head is another matter, and then you need to affix mirrors on long arms, best would be aluminum or fiberglass for weight, but some light and strong wood like balsa might be ok too, with aluminum mounts for the LCD and helmet.

For that matter I am sure cardboard would work if cut and attached properly, but first the basic geometry needs working out.

nubie this is quite a phenomenal idea but I don't get it completely. So you want to mount the LCD panel to the motorbike helmet then the LCD panel reflects into a mirror and then into the motorbikes visor? Does this mean the visor will actually get a full field of view wrapped around your eyes?

The theory for this is the same as a pico-projector (replace mirror with a screen), but as far as I know there aren't any HD pico-projectors yet, and they don't cost under $200 apiece like a simple LCD does.

You can read on microvisions site here http://www.microvision.com" onclick="window.open(this.href);return false; they have been awarded by the us military $750,000 to be build a 720p pico projector but that won't probably be out till another 18 months. I can tell you that the microvision pico projector doesn't need optics or mirrors if that helps.

[nubie]

nubie this is quite a phenomenal idea but I don't get it completely. So you want to mount the LCD panel to the motorbike helmet then the LCD panel reflects into a mirror and then into the motorbikes visor? Does this mean the visor will actually get a full field of view wrapped around your eyes?

No, pretend the visor isn't there, I just liked the look of the helmet.

You will be looking through the mirrors directly at the screen, the mirrors do nothing but allow the LCD to be placed the best for weight distribution.

Here is a picture of how it would work without mirrors, very bulky and long as well (unless there are optics for the LCD to make it appear far away):

I will pretend i havent seen that.

OK, why? (I think it is supposed to be cheesy, gives it a naive charm), it is just the basics to help understand the concepts, and possibly as a proof of concept.

[nubie]

Sorry, should I start a new topic for generic HMD ideas?

My thinking is that with off-the-shelf stuff you could make an LCD one with 960x720 resolution per eye (and full 1080p when not in stereo.)

(PS I updated the first picture for clarification, your picture is deleted, so it will probably disappear.)

Here is the link to 15.4" displays, the 1920x1200 is expensive, but the 1280x800 is pretty cheap (that would be 640x400 per eye in a setup like I show) at ~$100 complete.

http://www.lumenlab.com/forums/index.ph ... =15376&hl=" onclick="window.open(this.href);return false;

That allows for different price levels, and 640x400 is OK for starting out, and might be acceptable with a head tracking system.

Huh, walmart has one for $110
http://www.walmart.com/catalog/product. ... ku=7754347" onclick="window.open(this.href);return false;

Might be OK for a proof of concept You could build an HMD for well under $200 with the right tools and skills.


Edit:

Here is one for $85:

http://www.pcconnection.com/IPA/Shop/Pr ... ku=9251586" onclick="window.open(this.href);return false;


Hey kekewons, what if you left the view at a long 640x800 and then just had it pan left to right on the head-tracking? Then you could mount it on a pivot and look directly into it.

I really wish I could find the optics they use in these HMD's (come to think of it I have the optics from a kids toy, I wonder where I put them), that would make it look like a bigger screen farther away, and maybe reduce eye-strain too.

[kekewons]

Well, one big attraction to using some system like this ("half HMD with moving monitor ceiling mount") is that you might be able to do it even using the new 22" 120Hz monitors+Nvidia shutterglasses kit...almost right off the shelf, and WITHOUT voiding any warranty on a $400 monitor (since the monitor itself will basically remain untouched. It'd just be mounted a bit differently is all).

Moreover, it might be possible too to expand the view using a full three monitor rig* (instead of just the center monitor), and thereby (possibly) realize something closer to a "full surround" view. Enough of one anyway that the sides might effectively almost "disappear" to the user, since he'd be so focused on the middle of his view.

[* I'm thinking of using "SoftTH" here, rather than a "Triple-head-to-go" hardware splitter, because SoftTH will allow the use of higher resolution monitors in all three cases. Doesn't hurt either that it's free. .

http://www.kegetys.net/SoftTH/" onclick="window.open(this.href);return false; ]

-----------

One big key to feasibility would be that the drive system that would swing the monitor(s) back and forth--specifically how powerful it would be, how quickly it could "get-up-and-go," and reverse direction too, to follow the moving head, etc.--would have to be quite good. Obviously the lower the overall moment of inertia of the mounted monitor(s) itself/(themselves), and the higher the power and "takeoff ability from a standing start" of the rotational mount (and the faster the refresh of the headtracking system too)...must all combine to make the effective headtracking of the monitors as seamless and lag free as possible. Any one of these, or any combination of them which is substandard might just make the whole thing a moving "dissappointment" (instead of a success)...but you never know until you try either.

BTW, I also have to wonder if it might help, too, to use one of your "dual planar" or "teleprompter" type mirrors, nubie, instead of just a normal first or second surface mirror, as a main viewscreen. My thinking here is that using this sort of "mirror-screen" might even make it possible to see your own hands (and perhaps the steering wheel, cockpit switches, or even mouse and keyboard) when necessary...WITHOUT having to raise the screen itself. This might be accomplished simply by "darkening the monitors(s) output" momentarily, while at the same time "lightening" the view of the "cockpit" (or desk) you are sitting at. Some combination of those two working together could perhaps do the trick....

Fascinating idea really.


k

[nubie]

BTW, I also have to wonder if it might help, too, to use one of your "dual planar" or "teleprompter" type mirrors, nubie, instead of just a normal first or second surface mirror, as a main viewscreen. My thinking here is that using this sort of "mirror-screen" might even make it possible to see your own hands (and perhaps the steering wheel, cockpit switches, or even mouse and keyboard) when necessary...WITHOUT having to raise the screen itself. This might be accomplished simply by "darkening the monitors(s) output" momentarily, while at the same time "lightening" the view of the "cockpit" (or desk) you are sitting at. Some combination of those two working together could perhaps do the trick....

k

Now this is a different thing altogether, and if you use a 70/30 mirror (more silver) and a blacked out room it should work.

Maybe a switch or something that will let you light up your hands to make them appear.

I envision a wrap around 3 mirror system that your head pokes up into, although at this point you could just use standard LCD panels as they shouldn't be in the way of the controls or anything.

[kekewons]

Exactly. A dark room and a cockpit light (perhaps working in concert with a monitor dimmer/killer of some sort).

It's occured to me that if you tilt your head when panning, the screen above would seem to "lozenge" (narrow or widen) at one end or the other...but it might not take too much practice to learn to turn the head keeping it more level. I suppose only experience would tell there.

--------

An additional feature: Perhaps add a dual (motorized) "tilt" system into the mix too. One that would tilt both the mirror screen and perhaps the monitors themselves up or down as the chin (and view direction is raised or lowered). There are practical limits to that, of course, but it might allow one to see a bit more "above" and "below" horizontal.

For use when "scanning the skies" to find the guy who's about to fill your nice aircraft full of holes, for instance....


k

[Okta]

Even if corrcetly counter weighted it will be far to heavy and bulky.

[nubie]

I'm not so sure, if a 15.4" panel is used, perhaps with the power supply and heavy metal frame removed it shouldn't be that heavy.

This isn't a real solution for VR, and I would rather build a room with 3 walls projected first for that. (do a one LED IR tracking system and only track left to right).

As for the HMD I suggest, I think it would be fine to get the 3D feeling. Using thin mirrors backed with balsa should take down the weight.

As far as total weight goes, the human neck is amazingly strong (http://www.md.ucl.ac.be/iepr/loco_rec6EN.htm" onclick="window.open(this.href);return false;), with a little exercise and practice it could be fine to support up to 15lbs easily. I am worried about the rest of the spine, a good lumbar supporting chair is a must.

I would actually like to take a standard helmet, then remove material and add the mirrors/LCD until it comes out the same weight it started, after all helmets conform to a legal code of safety, and they are designed to be worn for long periods .

Things I can think of: lose the metal frame, or make one of thinner metal, remove unnecessary electronics, use special thin and flexible cords. Build a one piece frame of thin board to hold all mirrors.

Man, I really want to proof of concept this, ach, time to put it on the shelf I guess.

[smoothy]

I really wish I could find the optics they use in these HMD's (come to think of it I have the optics from a kids toy, I wonder where I put them), that would make it look like a bigger screen farther away, and maybe reduce eye-strain too.

I was in contact a while ago with a company called LEEP VR, they designed the optics for many of the HMD's of the past. Like the ones you would find in VR games and rides in the arcades as well as in disney land. If you go here http://www.leepvr.com" onclick="window.open(this.href);return false; you can read many things about the work they had done over the years. Unfortunately the site hasn't been updated since 2006. Back then I was in contact with them and they were working on a new full human visual field of view HMD but since then I have heard no word on this thing coming out. They had optics back in the 80's and 90's which were able to offer 80 degrees, 120 and even 160 degree field of views. Of course these were really expensive. One interesting HMD they made would sit on a table stand you can see that here http://www.leepvr.com/08cyberface3.html" onclick="window.open(this.href);return false; there new HMD is the cyberface x which is yet to come out http://www.leepvr.com/15cyberfacex.html" onclick="window.open(this.href);return false; I of course would prefer if we could just create a light HMD not something that sits on a stand as this means your tied to small movements where as in a fps I want to move around 360 degrees with head tracking and this wouldn't be possible.

[crim3]

It looks like most of us been there and dreamed of that cyberfacex.
I find very interesting the history of how it all began. Those self-designed optics for full FOV stereoscopic photography, very inspiring.

I also was worried about the lack of updates and contacted them a few months ago. They told me that everything was still running up and cyberfacex was in development.

[kekewons]

Nubie, you must have either a backlight for the LCD to even see it (which effectively brings you so close to the overall weight of a monitor that it might just as well be one), or you must use projection lamps and shoot light through it, thereby turning it into a projector anyway. So I wouldn't count on taking much weight out of it using just a panel alone.

This is why I favor the ceiling-overhead mount if using a monitor.

---------

On the other point (the on-off toggling telepromter mirror/screen)...would you know how thin and light the glass or plastic substrate is in these things? The thinner and lighter the better, it seems to me, unless it's so flimsy that it begins to bow. Glass, in particular, won't stand much of that, and it'd be only a matter of time until it broke.


k

[smoothy]

It looks like most of us been there and dreamed of that cyberfacex.
I find very interesting the history of how it all began. Those self-designed optics for full FOV stereoscopic photography, very inspiring.

I also was worried about the lack of updates and contacted them a few months ago. They told me that everything was still running up and cyberfacex was in development.

It's good to hear that the cyberfacex is still in development

[nubie]

Nubie, you must have either a backlight for the LCD to even see it (which effectively brings you so close to the overall weight of a monitor that it might just as well be one), or you must use projection lamps and shoot light through it, thereby turning it into a projector anyway. So I wouldn't count on taking much weight out of it using just a panel alone.

Sorry the dozen disassembled LCDs in my room beg to differ, the "backlight" is made of acrylic and PVC, with one or two small CCFL lights.

Most of the weight is a heavy internal frame. Considering the $85 price of the monitor (AKA a complete PC style monitor), it may have a minimal metal frame, or no metal frame at all to save cost.

On the other point (the on-off toggling telepromter mirror/screen)...would you know how thin and light the glass or plastic substrate is in these things? The thinner and lighter the better, it seems to me, unless it's so flimsy that it begins to bow. Glass, in particular, won't stand much of that, and it'd be only a matter of time until it broke.

I don't really follow, I was only thinking of a HMD.

I don't really understand why you want to mount the display to the ceiling, it offers no benefits that I see. Either you want VR or you want 3D, or both. VR is going to be head mounted, or you can get minimal VR by extra-wide projection.

Anything you can achieve by putting the LCD on the ceiling can be achieved by putting it where it belongs, in front of your view.

3D adds more into the mix. All I can say is start experimenting, build some stuff and get a feel for the results, then make a decision.

If I was looking into this I would seriously consider the $800 - $900 Mitsubishi or Samsung 1080p 3D supporting monitors (I think it is checkerboard with a 3D glasses output jack), this might work with iZ3D as the monitor is in charge of the shutter sync.

At 50" to 60" you will see a lot, and you can even build it into your cockpit. Supplement with 2 more for surround o'vision and use the TrackIR system (commercial $130) for the VR effect.

I really think you need to try these out for yourself to get a feel for what you want. Go somewhere with demos and see if they will let you demo the 3D.

[nubie]

I really wish I could find the optics they use in these HMD's (come to think of it I have the optics from a kids toy, I wonder where I put them), that would make it look like a bigger screen farther away, and maybe reduce eye-strain too.

I was in contact a while ago with a company called LEEP VR, they designed the optics for many of the HMD's of the past. Like the ones you would find in VR games and rides in the arcades as well as in disney land. If you go here http://www.leepvr.com" onclick="window.open(this.href);return false; you can read many things about the work they had done over the years. Unfortunately the site hasn't been updated since 2006. Back then I was in contact with them and they were working on a new full human visual field of view HMD but since then I have heard no word on this thing coming out. They had optics back in the 80's and 90's which were able to offer 80 degrees, 120 and even 160 degree field of views. Of course these were really expensive. One interesting HMD they made would sit on a table stand you can see that here http://www.leepvr.com/08cyberface3.html" onclick="window.open(this.href);return false; there new HMD is the cyberface x which is yet to come out http://www.leepvr.com/15cyberfacex.html" onclick="window.open(this.href);return false; I of course would prefer if we could just create a light HMD not something that sits on a stand as this means your tied to small movements where as in a fps I want to move around 360 degrees with head tracking and this wouldn't be possible.

That looks sick! (I hope the MSRP is under $1,000 and comes with an iZ3D license )

Wow, they really went all out for that didn't they? The skull pic is chilling, and the NASA helmet is just plain cool.

[Okta]

If you choose a single display option using the iz3d split screen stereo aspect ratio becomes an issue. I suppose if you design clever optics the view could be stretched horizontaly. I have been using a pixi viewer to use the driver.

[smoothy]

are you guys still working on making this 3d helmet?

[agniusm]

http://www.kopin.com/sxga/" onclick="window.open(this.href);return false;

[crim3]

http://www.kopin.com/sxga/

Too expensive, too little.