As adapted Android to virtual reality? # Io16 – dobreprogramy

Google has placed on virtual reality. Design
 Daydream, expand toy cardboard Cardboard in
 something that will bring real experience VR on smartphones
 It promises to be quite interesting. Smartphones Certified
 “Daydream ready” will be a lot. During the opening I / O 2016
 the presentation we met but only the basic assumptions
 google’owego approach to VR. Time to look at it all
 closer.
                         
                         
 

r e k l and m and

The basic problem with the VR – it must be really smooth, far away
 more fluid than that to which we have become accustomed interfaces
 Screen Display. The world of virtual reality should in time
 respond to real user traffic, otherwise
 his impression of unreality will “beat the eyes.” This
 just thinking they had the developers of Google, speaking about the delay
 the movement of the photon – how fast you can display pixels
 response to changes in head position.

To help minimize delays, Android received N
 a special mode of operation. After the new system,
 certified device will be able to activate the new mode in
 the whole thread to draw the user interface is opened
 divisional core processor. The second core is the
 reserved for the use of sensors, ie. the gyroscope and accelerometer.

This is not the end of changes. Also changes the stream of drawing
 the contents of the screen by the GPU. Normally Android is used
 double-buffering: the screen displays the contents of one frame,
 while the GPU draws the contents of the second frame buffer. After
 refreshes the screen contents of the buffer is transferred to the screen,
 while the buffer is drawn next frame. this protects
 from error propagation of the screen, but also slows down
 drawing. In VR mode Android will be so drawn directly
 on the screen as quickly as possible, trying to keep
 synchronization frames drawn by the GPU cycle refresh
 screen.

For all this there is known, eg. from the Oculus Rift shift mechanism
 temporal (time warp), which in a clever way reduces
 perceptible delay. What is the trick? Think about
 normal rendering pipeline virtual world:

1. fixed position is the user’s head
    
2. is set to the position of a virtual camera
    
3. to this perspective is drawn view of the world
    

 At 60 FPS, which expected
 are virtual reality Daydream, it means that we have to
 there are 16 milliseconds to measure the position of the head,
 draw the world, and displays it on the screen. 16 ms is very
 enough, the average human reaction is approx. 200 ms (although trained
 Asian players react at 100 ms) – but if someone
 will just move his head, the angular offset this
 time is big enough to notice the difference between
 measurement of the first step and the prospect of the third step. What
 you can do in this situation? Time shift work on
 already drawn frame, measures the movement of the head made during these 16
 ms and introduces the final amendments before being displayed. In practice
 this reduces the apparent delay by up to half.

All of these changes have led to dramatically reduce
 delays. Even fast smartphones with Android 6.0 (eg. Model
 Here Nexus 6P) have been registering a delay of over 100 ms – enough to
 It was visible to everyone. The Android N delay reduced
 to less than 20 ms.

Of course, that these changes were possible, Android must be
 running on the appropriate hardware. So far it meets them
 only one smartphone – Huawei Nexus 6P. Recall his
 parameters: the CPU is octa Snapdragon 810 GPU to system
 Adreno 430, to 3 GB of RAM – and most importantly, the display
 not just any, but WQHD (1440 × 2560px,
 518ppi), made in AMOLED technology. Yes, displays
 liquid crystal fall, no smartphone screen LCD
 Certificate of compliance with google’owym VR will not get, wake cycle on and off pixels here is not fast enough.

The success of this initiative depends on the time manufacturers
 hardware – if they could enter the time machine
 attractive prices, and not only the flagship that would satisfy
 requirements? For its part, Google has done a lot,
 providing in addition to the operating system as reference
 goggle-holder for smartphone and wireless controller. Will appear
 a special variety store Play, software conceived
 specifically for virtual reality. As an alternative to a
 expensive VR goggles for PCs, smartphones solutions can
 to conquer the market, especially among young people – what you see
 even after review
 VR kit Samsung pen Matthew Wake up.