Virtual reality glasses "budget" (so far without a tracker)

I want to share the experience of assembling and adjusting simple and affordable glasses for viewing 3D content.

First I made FPV glasses with a Fresnel lens and a 7 ”IPS matrix .

Here are just a tracker based on infrared LEDs and a web-camera turned out to be capricious. At least I could not properly debug it. The image is displayed by a clone of the main monitor from a desktop computer's video card via an HDMI cable.


')
The advantages of this design include:

• fairly wide angle of view;
• focusing to infinity did not cause eye fatigue;
• very light optics (literally a few grams).

By cons:

• Fresnel lens (focal length - 200 mm) gives the image is not very good quality, especially on the periphery of the screen;
• significant chromatic aberration (color halo around objects on the screen);
• the glasses turned out quite bulky due to the large focal length of the lens;
• they cannot achieve stereo effect, since the image for both eyes is common.

Decided to move on. A thought arose on the basis of the same matrix to make a more short-focus design with the possibility of 3D – vision. And, if possible, connect a more advanced tracker on solid-state gyros.

From the Fresnel lenses refused, as the base I chose these 3D glasses .

Their focal length was about 80 mm. Lenses flat - convex, plastic. There is even an adjustment of interpupillary distance.

Assembling and adjusting points

First of all, I disassembled them and blew out inside and outside the black matte paint to avoid excessive glare. That in general, it is not necessary to do. Lenses and straps left as is.



Immediately before me was the question: at what distance from the lenses to place the screen? Determined the focal length of the "solar test." Led the lens to an infinitely distant source of light - the sun. Measured at what distance the light beam gathered in the smallest spot size.



The method is not precise, but quite accurate. Allows you to find the focal length of the lens.



If it is at this distance to place the screen, then the diverging light flux from each pixel, passing through the lens, will be parallel. Thus, the image will be like in infinity, which is necessary for comfortable perception. This adjustment method is suitable for normal vision and the picture on the screen is clear from any distance.

The original design, I do not know why, did not meet this criterion. Points went to remake. The screen is placed a little further - at a distance of 83 mm.



The board is well located outside the glasses flap.



Draped the edges with black isoplen to avoid lateral flare and dust.



The first views of 3D pictures and clips side by side from the network impressed me. It's amazing that such a simple, I would even say a primitive construction, can give such an effect!

Some particularly dynamic scenes can literally roll! After watching plenty of 3D pictures, videos and movies, I decided to move on.

The question arose - what about the 3D effects in games? In particular, auto, air and other simulators. What can this effect be incorporated into? There are a lot of solutions, various glasses, specialized monitors are used ...

I found the appropriate iZ3D driver . It is rather old, no longer supported by the developer, but compatible with many games! It has several modes. I needed - side by side and without anamorphic compression. In the program's config file, this is mode 2. The side by side mode is trial, for 30 days.

The program generates two images with parallax. It is configured, and directly from the game, stereo and toe. There are three presets, for each game the driver creates a profile. There are some glitches with shadows, clouds. Where necessary, have to turn them off.

Tested with the games LockOn 2 and Orbiter 2010. These are simulators, aviation and space. No tracker yet.





Games, I would say, began to play with new colors and are perceived in a completely new way. Objects have become convex, there is a volume of the surrounding virtual space. The field of view is large.

My NVidia GTX 275 graphics card easily handles the creation of a stereopair. The board by today's standards is not particularly powerful ... The image of the main monitor was duplicated on its glasses, adding brightness.

What happened?

Still can be attributed to the pluses:

• wide field of view;
• focusing to infinity does not cause eye fatigue;
• small, almost invisible, chromatic aberration;
• the interpupillary distance is regulated;
• The relative compactness of the glasses provides 3D viewing comfort.

Were found and disadvantages which, as is well known - the continuation of the merits.

I'll take them to:

• visible grid of pixels and the slightest motes on the screen (flannel to help);
• the resolution is divided equally, so that each eye gets half of the horizontal resolution (2K matrix 6 ”and above can change the situation for the better);
• the absence of external landmarks in dynamic scenes can and does cause, at least in me, tangible vestibular discomfort;
• to improve perception, it was necessary to cover the edges of the matrix with tape, since it is wide even for my interpupillary distance (I have 70 mm);
• The human visual analyzer detects parallax, but the necessary accommodation is not required, focusing and so on to infinity, so you need to get used to such an image.

The matrix of my dreams

The matrix for such an optical system would be desirable:

• more resolution (I have 1280 X 800 pixels);
• smaller diagonal (I have 7 ”, 150 X 94 mm).

The width should be equal to twice the interpupillary distance (140 mm for me, the height is equal to the interpupillary - 70 mm). The screen resolution is at least twice as good. I have 8 pixels per mm, i.e. need 16 pixels.

Thus the matrix of my dreams should have the following characteristics: 6 inches diagonal and 2240 X 1120 pixels resolution (140 X 16 (width) and 70 X 16 (height)). And of course a powerful graphics card!

Eventually

The time spent on the manufacture and adjustment of stereoscopic glasses (literally a couple of days) was not wasted. 3D effect is present!



Glasses are not expensive, allow a new look at the old and rather boring games. It remains only to connect an adequate tracker and with it plunge into virtual reality already at a new, not yet known level.

Tracker

I want to collect this . And I would have collected it, but the post office corrected my plans. Waiting for a parcel from China with boards and sensors for the tracker.
Finally collected!