[DIY] HMD with Wide FOV and Stereoscopic

[Markurt]

Hello,
My Name is Marc. I'm french (so don't blame me if my english is not so good )

I'm interested a lot on Virtual Reality, but, as everyone interested in VR , I'm a little bit disapointed that there is no really great HMD on the market. (I mean at consumer level)
I tried a lot of HMD for understanding which way was the best way to go.

What is really important with a HMD ? What do I need to feel Immersion ? What is the price to paid to have something good ?
Of course, it exist a lot of descent HMD on the market , but what everyone expect (Wide FOV , godd quality pictures, good headtracking and of course STereo 3D easily supported) is not going to happen nowadays. We'll have to wait a little.
So I decided to Build a Optical Box , containing screens, optical stuff, and one day I'll find a way to fix this box on some kind of plastic helmet to have a real HMD.

My work is not finished, but I wanted to share what I've done already.
1 - The global look of the optical box (at this time only one screen is working because I miss a second universal power supply)

BILD0049.JPG

2 - Getting closer to the right screen to see what we can see inside

BILD0052.JPG

3 - Closer again

BILD0053.JPG

For that "first optical box try" i used :
- 2 x 3,5 LCD screen found on eBay (it cost me almost 20$ by screen) => They are not so good, but One day better screen from this size will be cheaper.
- Balsa Wood for the "box" to carry everything (not a very good choice , because balsa is very easy to break) => Around 10$ for 2 piece of 1m
- 2 PVC Coupler (almost 6$ on any store)
- All optics needed as shown on the very good tutorial http://www.vrtifacts.com/hmds/leep-on-the-cheap/" onclick="window.open(this.href);return false;
=> It's perfect to achieve some kind of LEEP Optics easily.

So with this box , I was able to Get Dual Input Stereoscopy (with IZ3D In dual projector mode)
Field of view is something around 100° (maybe a little bit less) so it's very nice !
Of course the Box is heavy , But I think this issue can be solved by mounting everything on a plastic helmet, and putting all the wires on the back (to counterbalance the weight)

My Next improvments will be :
- Get a better Box to fit everything inside (I Think I can reduce the box size)
- Change the material for making the Box => No idea at this moment ....
- Add a HeadTracking inside the box (for that it's easy => Using a Gyration GyroMouse will provide a 2DOF HeadTracking for cheap) => Maybe also a FreeTrack support by adding LED on the Box ...it will extend the HT capabilities
- Get Better LCD => Any Idea ?

Have a Nice a day ,
Marc.

[cybereality]

Wow, very cool man. Looks like you have a nice project there. How hard was it for you to build the LEEP optics? Was it expensive? I still have dreams of building the ultimate HMD one day. You give me hope.

[Okta]

Nice work. A few questions. What are you using to drive the lcd's? I have some similar screens and i bought 2 cheap vga to rca converters. The leep optics setup seems to be designed for 2 inch screens? Are you losing the edges of your screens then? Are you using the 3m fresnels? Do they work well?
And how much did you spend on the optics parts?

Cheers.

[Markurt]

Hi Okta , Hi Cybereality,
Thanks for your posts !
@Cybereality => Glad to had give you a hope ! By reading all the "do it yourself" part of this website , everyone building a HMD give me a lot of hope for doing that ! It's nice to see that there is a community that still believing in VR , I mean VR as it was promised in the year 90s . But for what we expect in HMD , unless we can Buy a Sensics X-sight (or wait until the CyberfaceX is released) , the only way is trying to build something, or at least , make some tries to find the best way to go.

Building the LEEP Optics was not so hard. I think the Hardest part was to manage the smallest lens for holding well at a specific distance with the larger one.
SOme pictures of the "Box Building" :

LCD_BOARD2.png

LCD_BOARD.png

OPTIC.png

OPTIC_LCD.png

The Lens costed me around 50€ for 2 sets (2 small lens , 2 large lens + shipping to France)
I guess it's less for people living in USA.
The PVC coupler was something around 5€.
I used small piece of Balsa to fit for the smallest lens. (as you can see on picture)
After that , on the box, I used Aluminium Tape to help have everything holding together.

@Okta => You're right LEEP OPTICS are designed for 2" LCD (or maybe 2,5" LCD), But, unfortunately it's very hard to find cheap LCD from this size.
And the Drawback is that , I cannot see all the screen through the optics. I Lose the edge of the screen.
I made some test with a BASE JUMPING game => Losing the edge is not really a problem when you're able to look around moving your head. It can be a problem if you want to have information on the screen, but, beside the resolution of thoses 3,5" screen, nothing small is really readable ! (I hope with Higher resolution screen it would be better)

The LCD are plugged into my PC using PC/TV converter (2 unit needed for stereoscopy). The LCD drive RCA input , and need a POWER SUPPLY each one. So I'll have to create a Box to manage this (using 1 DC for powering both screen) I'm not very good on electronics, so for the moment I'll just use splice for DC wires.
I don't use 3M fresnel ... I 'm not very familiar with fresnel .. What can be the benefits using Fresnel ?
(I"m a Newbie in optic world)
LCD works well . The only problem I get , was that the Wires was not very well soldered (i don't know the english word) on the board , so I had to solder them again .(hard because it's very small wires....)

I was able to make a test with the 2 screen powered : It's impressive to have a wide FOV (it seems wider than in MRG2.2). Even with very low resolution, the immersion feeling was great. Periphel vision is covered by the pictures. It's necessary to move the eye to look around (if you move a lot, you can see the PVC coupler LOL) . The focus is good : I mean you don't have the feeling of having a big screen just in front of your eyes ... so that's cool .

Now the goal is to find another material for the box ...

Have a nice day,
Marc.

[Okta]

Thanks for the reply. I was referring to the 3m fresnel lens mentioned in your vratifacts link 3M Press-On Fresnel Prisms.
That is needed to offset your vision because the 3.5inch screens are too far apart for your eyes. See my picture here
Here i used 2 lenses offset to redirect my eyes to the center of the 3.5 inch screens.

How did you manage?

[Markurt]

Ok I understood ....

Well when I look inside my HMD , I don't have feeling that screen are too far apart.
I mean, I can see both pictures (merged in one) without problem. I just aligned the optics exactly the same way on each screen (to be sure to see exactly same picture in 2D mode) => result is OK ...

But I thought it might be possible to have 2 separate little box containing each Optical system (Screen + Optics) and to slightly rotate then to make them be really in front of the EYE .... Like the WIDE5 from FakeSpace Labs..
http://www.fakespacelabs.com/Wide5.html" onclick="window.open(this.href);return false;

But I'll make some tries using fresnel ...it can be very helpfull ...

Thanks for the info !!!

[Markurt]

Hello ,

Look at this website ..
Nice place to buy Cheap LCD screen
They also sell 2" and 2,5" .....
http://www.lcdtft.com/?gclid=CIuamNfzyqYCFQ8f4QodOTBuIA" onclick="window.open(this.href);return false;

@++

[PalmerTech]

AEIcomp is overpriced, I know from years of experience. They are just reselling what you can get elsewhere for much, much cheaper.

This is a much better price, and free worldwide shipping! They will even mark as a gift, for countries with import tax.

http://www.dealextreme.com/details.dx/s ... r.87419775" onclick="window.open(this.href);return false;

[cybereality]

http://www.dealextreme.com/details.dx/s ... r.87419775" onclick="window.open(this.href);return false;

That display doesn't look bad for experimentation. Although the resolution seems really low, probably not that great for gaming. The price is nice, though.

[PalmerTech]

Yeah, it is 320x240. It can be modded for S-Video, a little better than composite.

[Markurt]

Hi Everyone,
Thanks for your answers !
I'll probably order 2 LCD 2,5" screen from Deal Extreme to make other tests with FOV, and find a way to reduce the overall size of the optic box !

@++

[bobv5]

"They will even mark as a gift, for countries with import tax."

Yeah, everything I bought from that place was labled as a pencil.

How is the distortion with these optics? I was looking at the leep site, looks like it would be pretty bad without the software to correct the image.

Also, those same screens are cheaper on ebay, at least for UK buyers.


http://cgi.ebay.co.uk/2-5-TFT-Color-LCD ... 3cb246826d" onclick="window.open(this.href);return false;

[Johnny-Mnemonic]

Great work Markurt!
Still MRG2.2 is best HMD I have seen because of FOV, even with low resolution, FOV plays major role in immersion, and now you actually have proved ability to build HMD with even wider FOV and stereoscopic!
Amazing, good luck in your further experiments!
Now I'm thinking on building of similar setup too!

Maybe I can help with some info on feasible 3DOF wireless tracker!
Check this mouse:
http://www.hillcrestlabs-store.com/serv ... ter/Detail

I've used prototype of this device, it can work in both modes - simply like mouse, with relative 2 DOF.
And using VRPN server http://www.cs.unc.edu/Research/vrpn/ as really amazing 3DOF tracker for home-brew applications.
Freespace tracker is very stable and don't need for calibration, working much better than built-in VR920 tracker for example, besides it's wireless.

I've used this tracker with my MRG2.2 as 3DOF tracker in small demo app, and result is very immersive.

[Markurt]

Hi Everyone,
And thanks a lot for your answers.
And of course thanks a lot for the links for cheaper screen.
I'll probably make a v2 of the box, using smaller LCD !

Johnny mnemonic => Amazing mouse !. Does the mouse include a Third axes, or the roll is achieved by some "cheat" with the 2 other angles ? by the way , it look like very very cool !

I'm also making a VR Application using DarkBasic.. trying to create an environment to walk inside and to interact with object, character, etc .... I've already made some lines of code to manage movement in the 3D world. i'm now also working on "How to be able to have interaction with a character using vocal command" .. I planned using Voice Buddy or VR commander...it's easi to assign a Key to a specific Vocal Command.... so easy to add..I also planned to have P5 DATA GLOVE usable in this application. (there is the necessary plugin to manage P5 DATA GLOVE in DarkBasic Pro).
For the moment tracking is managed using mouselook and a gyromouse...but If it's possible to had roll ...

For the HMD design , look this video :
http://www.youtube.com/watch?v=DzrlOzmtCV4" onclick="window.open(this.href);return false;
at about 1minute , you'll have a view of the inside.
It gave me idea for my design : i think I'll go using Welding goggles, for the part where you put your head.And after that, fix the Optical box (reduced of course ) on the goggles. I'll pass all the wires on the back to counterbalance the weight . Stills the problem for the Optical Box : use the PVC coupler ? or try to fix the lenses in a different way ? Use balsa wood or go for other material ? maybe real wood (i mean light one , easier to attach and much more resistant than the balsa one for holding heavy optics)I don't know really know.
The HMD in the video is what I want to make ... Almost the design ... It don't seems so hard , even If I'm pretty sure that it will be very very very very hard to have something really usable.

Have a nice day ,
Marc.

[bobv5]

couple of screens here that claim to have higher res. No idea if they really do...

http://www.goodluckbuy.com/rc-2512-2-5- ... ixels.html" onclick="window.open(this.href);return false;

http://www.goodluckbuy.com/3-5-tft-lcd- ... -3500.html" onclick="window.open(this.href);return false;

[Johnny-Mnemonic]

Johnny mnemonic => Amazing mouse !. Does the mouse include a Third axes, or the roll is achieved by some "cheat" with the 2 other angles ? by the way , it look like very very cool !

I'm also making a VR Application using DarkBasic.. trying to create an environment to walk inside and to interact with object, character, etc .... I've already made some lines of code to manage movement in the 3D world. i'm now also working on "How to be able to have interaction with a character using vocal command" .. I planned using Voice Buddy or VR commander...it's easi to assign a Key to a specific Vocal Command.... so easy to add..I also planned to have P5 DATA GLOVE usable in this application. (there is the necessary plugin to manage P5 DATA GLOVE in DarkBasic Pro).
For the moment tracking is managed using mouselook and a gyromouse...but If it's possible to had roll ...

To be clear, I didn't used exactly this mouse but I had two prototypes of it, so it should work the same with final version
So, this mouse can actually work in two modes:
1 - simple "mouse" emulation, like gyro mouse
2 - true 3 degree of freedom (yaw, pitch, roll) tracker, it's no trick, all axes work independently and work very good. To work with this mouse in tracking mode, you need to use either FreeSpace SDK, or VRPN server configured on FreeSpace trackers.

I don't know is there ability to include such support in DarkBasic, but should be possible, at least it's easy and pretty straight-forward with regular C++.
SDK can be downloaded from FreeSpace website for free.

[Okta]

couple of screens here that claim to have higher res. No idea if they really do...

http://www.goodluckbuy.com/rc-2512-2-5- ... ixels.html" onclick="window.open(this.href);return false;

http://www.goodluckbuy.com/3-5-tft-lcd- ... -3500.html" onclick="window.open(this.href);return false;

I think its a little to good to be true, they claim 640x480 image resolution which is most certainly interpolated for that prices range and all other products in that range are 320x240.