Tero SarkkinenOctober 19, 2016

AR&VRLatencyIlls

Image courtesy of Zero Latency

WideSpectrumofApplications&PerformanceRequirements

360videos BasicVRandARapplications

High-endVRandARapplications360pictures

Requiredperformance

WhatIsLatency?

Motion– to – photon

1 2 3 4 5 6 7

Userdoessomething• Tiltshead• Moves

position• Moves

controllers

HMD/controllerdetectsthemovement

Signalissenttothesimulationsystem(embeddedinHMD,drop-inphone,ortethered(PC,PS4)

Simulationsystemcalculateshowimageshouldbechanged

Simulationsystemcalculatesthenewimage

Simulationsystemsendsthenewimagetothescreen(embedded,drop-in,tethered)

NewimageisshownintheHMDscreen

HMD HMD IO System System IO HMD

Application– to– photon

LatencyTesting– WhattoTest• 45/60/90fps

– 22/17/11ms/frame

• Droppedframes– Calculatedframesthatwerenevershown– indicatestooslow

renderingsubsystem

• Duplicateframes– Usuallycausedbyasynchronoustimewarp

• Screenpersistence– Lowpersistenceprovidesbetterexperience

• Lefteyevsrighteye• KeepaneyeonimagequalityJ

VRTrek™, a latency testingdevice by Basemark

Scoop!

World’sfirstindependentlatencytestresultsforthemostpopularVRHMDs

Systemusedforthetests:Windows10,Inteli5-3570k@3.4GHz,16GBDDR3,NVIDIAGTX1080Softwareused:VRScore (Beta)by Basemark

24,16

21,72

20,94

19 20 21 22 23 24 25

OculusCV1

HTCVive

OSVR

ApplicationtoPhotonLatencyinMilliseconds(SmallerIsBetter)

What’sPerformance?

• FPS(min,max,average)• Howmanyframeswereslower

thanallowed?• It’sparticularlyfataliftwoor

moresubsequentframeswereslowerthanallowed

• SomeHMDsswitchto45FPSiftheydetectthatthesystemcan’tkeepupsteady90FPS

HowtoDoPerformanceTesting

• Useindependentreputablebenchmarks,e.g.VRScore

• Independentlabtestingandcertifications,e.g.TÜVRheinland

• Testingprojects,e.g.Basemark

PerformanceOptimization• HMD

– ChoosetheHMDwiththesmallestapplicationtophotonlatency– UsethelatestHMDSDK(drivers)

• System(PC)– ChoosethegraphicscardandCPUaccordingtoyourapplication’sneedsandmakesureyou

usethelatestdrivers– Makesureyouhaveenoughsystem(RAM)memoryandthatthememoryisfast

• System(All-in-oneanddrop-in)– Choosethedevicewiththesmallestapplicationtophotonlatency

• Application– Designyourappsuchthatitdoesn’tutilizeprogrammingtechniquesorgraphicsdesignsthat

areillsuitedfortheparticularCPU,GPUorSoC youareusing– Utilizeasynchronoustimewarp,multiresolutionrendering,etc.– MakesurethegraphicsengineyouhavechosenhaspropersupportforVRoptimization

techniques– Optimize.Measure.Repeat

PerformanceOptimizationResources

AMDhttp://developer.amd.com/tools-and-sdks/graphics-development/liquidvr/

NVIDIAhttps://developer.nvidia.com/sites/default/files/akamai/VRWorks/VRWORKS_Technical.pdf

Oculushttps://developer3.oculus.com/documentation/intro-vr/latest/concepts/bp_intro/

Basemark- TheWorldLeadingGraphicsExperts

VRScore™ IndependenthighqualityVRbenchmark

VRTrek™ VRHMDlatencymeasurementdevice

RockSolid™ IndustrialgradeAR/VRgraphicsengine

ProfessionalServices Graphicsperformanceoptimization