Introducing WebVR

Dave Evans - CTO, PlayCanvas

What is VR?

Head-mounted Display

Accelerometers to track position and orientation of head

3D rendering of virtual world

Desktop

Mobile

How does VR work?

Render your scene

Render twice - L + R

Apply post effect

How does WebVR work?

Render scene to canvas

Render L + R to canvas

canvas.requestFullscreen()

Can I use WebVR?

Not in your normal browser

Chrome: tojicode.com

Firefox: blog.bitops.com

Javascript API

WebVR API

navigator.getVRDevices()
navigator.mozGetVRDevices()
canvas.webkitRequestFullscreen({vrDisplay: device})
canvas.mozRequestFullScreen({vrDisplay: device})

navigator.getVRDevices()

requestFull(s|S)creen()

HMDVRDevice

device.getEyeTranslation()
device.getRecommendedEyeFieldOfView()
device.getCurrentEyeFieldOfView()
device.getMaximumEyeFieldOfView()
device.getRecommendedEyeRenderRect()

HMDVRDevice

device.getEyeTranslation()
device.getRecommendedEyeFieldOfView()
device.getCurrentEyeFieldOfView()
device.getMaximumEyeFieldOfView()
device.getRecommendedEyeRenderRect()

WTF?

device.getEyeTranslation()

leftOffset = device.getEyeTranslation("left");

rightOffset = device.getEyeTranslation("right");

Used to offset left and right cameras

Which one to use?

​​device.getCurrentEyeFieldOfView("left");
device.getMaximumEyeFieldOfView("left");
device.getRecommendedEyeFieldOfView("left");

Which one to use?

​​device.getCurrentEyeFieldOfView("left");
device.getMaximumEyeFieldOfView("left");
device.getRecommendedEyeFieldOfView("left");

You'll always be good with this one

RenderRect

device.getRecommendedRenderRect("left");

device.getRecommendedRenderRect("right");

May not be needed

PositionSensorVRDevice

sensor.position
sensor.rotation

Vector and Quaternion

Sensor in use

This is usually wrapped up for you

Library Example

PlayCanvas

input_hmd.js
var hmd = new pc.input.Hmd();
hmd.poll();
hmd.position;
hmd.rotation;
hmd.fullscreen();

Library Example

PlayCanvas

oculus_camera.js
context.systems.script.addComponent(entity, {
  scripts: [{
    url: "oculus_camera.js"
  }]
});

Performance

Latency

Time between:

  1. move head
  2. screen refreshed

Latency

Under the hood:

  1. move head
  2. sensors detect change
  3. sensor data received by application
  4. application logic
  5. scene rendered
  6. screen refreshed

Only two of these controlled by you

  1. move head
  2. sensors detect change
  3. sensor data received by application
  4. application logic
  5. scene rendered
  6. screen refreshed

Latency

Current Problems

Oculus DK2 runs at 75Hz

Browsers run at 60Hz

Runs badly on integrated graphics cards

e.g. MacBook Pros :-(

Summary

Summary

WebVR is super fun to play with


Very early days, but massive potential


Libraries should make this stuff easy to use

Thank you

Find out more: playcanvas.com

@daredevildave

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