Augmented/Virtual Reality

Augmented/Virtual Reality
founder:	stick
depends on:
interested:	biiter, tomsuch, ruza, aym, lexik
software license:	?
hardware license:	?

We have Vuzix iWear VR920 and shutter glasses available for projects.

• Depth Perception
  • http://xkcd.com/941/
• Kinect + VR
  • http://www.engadget.com/2010/12/21/kinect-paired-with-vuzix-vr920-shades-creates-zany-virtual-real/
• Plane Model + Cam
  • http://www.autoblog.com/2011/08/31/r-c-f16-jet-with-swiveling-pilots-view-blows-our-tiny-little-mi/
• Wireless Head Mounted Display
  • http://www.pabr.org/wxhmd/doc/wxhmd.en.html

Edimensional controller se inicializuje barevnyma kodoma v horni casti obrazovky. Kody se zjisti z programu E-D.exe na adrese 0x004010A9. Program si uklada nastaveni do registru v rutine na adrese 0x00401491.

Aktivace synchronizace LEFT/RIGHT obrazu se signalizuje pres DDC na VGA konektoru.

# modprobe i2c-dev
$ i2cdetect -l
$ cat /sys/bus/i2c/devices/i2c-X/device/device/card0-VGA-1/edid

• VGA (VESA DDC)
• Linux DDC/CI Tool page
• Using I2C from userspace in Linux

Bryle se ovladaji pres USB. USB descriptor zarizeni obsahuje krome audio kanalu a headtracking sensoru jeste display controller kterym lze prepinat obraz na levem a pravem oku.

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        4
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              4 VR920 3D Stereo Control
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x05  EP 5 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1

Ovladani displayu probiha na EP 5 OUT (0x05). Inicializace se provadi zpravou typu control transfer v nasledujicim nastaveni:

bmRequestType   0x40
bRequest        0x0009
wValue          0x0302
wIndex          0x0003
wLength         0x0010
data            0x02 0x07 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Kompletni inizializace zarizeni a ovladani leveho/praveho oka v PyUSB:

import usb

# nalezeni zarizeni
dev = usb.core.find(idVendor = 0x1bae, idProduct = 0x0002)
if dev is None:
  raise ValueError('Device not found')

for i in range(4):
  try:
    dev.detach_kernel_driver(i)
    dev.detach_kernel_head(i)
  except:
    pass

# nalezeni EP 5 OUT
epx = None
dev.set_configuration(1)
for cfg in dev:
  for intf in cfg:
    for ep in intf:
      if ep.bEndpointAddress is 0x05 :
        epx = ep

if epx is None:
  raise ValueError('ep not found')

# inicializace
dev.ctrl_transfer(0x40, 0x9, 0x302, 0x3, "\x02\x07\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
dev.ctrl_transfer(0x40, 0x9, 0x302, 0x3, "\x02\x07\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
epx.write("\x00")
dev.ctrl_transfer(0x40, 0x9, 0x302, 0x3, "\x02\x07\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")

# ovladani displayu
epx.write("\x00")
epx.write("\x01")

Obraz je v displayi udrzovan dokud mu neprijde zprava o jeho obnoveni (0x00/0x01).

Anaglyph_image

https://www.youtube.com/watch?v=2cJ1KCTem9o

Paul Bourke's stereoscopic articles