Unity和UE4開發(fā)VR的優(yōu)劣

#/7輕量級，安裝、調試和打包方便配置VR項目十分簡單學習成本低，文檔完善開發(fā)成本低UI系統(tǒng)在PS4上調試方便，有批處理文件可以一鍵運行AssetStore提供了一些VR下的Demo作為參考Unity的劣勢：內建工具不夠完善渲染差，光照系統(tǒng)糟糕，陰影bake有bug，只能勉強達到2A游戲入門水平對于控制器支持較差，一些如手柄震動、VR控制器空間定位的功能引擎未集成，需要第三方插件或額外代碼沒有材質編輯器，需要第三方插件Prefab不支持繼承沒有xx的LevelStream支持Unreal的優(yōu)勢：畫面效果完全達到3A游戲水準光照和物理渲染即便在縮水的狀況下也足以秒殺Unityxx系統(tǒng)，從此策劃不用再寫代碼強大的材質編輯器各種官方插件xx對于手柄、VR控制器支持良好提供各種游戲模版，用來做原型配合Blueprint甚至比Unity更快Unreal的劣勢：C++如果要開發(fā)PS4游戲需要重新編譯引擎，12核服務器，24線程編譯大概需要20-30分鐘如果需要重新編譯引擎，光拉代碼就需要至少一個小時創(chuàng)建新項目大概又要編譯十多分鐘如果切換平臺，要編譯幾千到上萬個shaderPS4部署不方便，打包編譯同樣非常久學習成本高，各子模塊功能強大但操作復雜部分功能沒有任何文檔，已有功能的文檔同樣不夠完善，不如Unity開發(fā)成本高，某國內3A團隊做了個10分鐘的VRDemo，據(jù)說已經(jīng)燒了一千多萬UI設計器非常之難用VR下的一些bestpractice同樣缺乏文檔和例子，目前都在摸石頭過河Buuuuuuuuuuug我覺得寫了這么多結論已經(jīng)很明顯了：小團隊沒錢追求快速出效果，對畫面要求不高的項目用Unity。中大團隊不差錢，買得起Unreal技術支持，分工明確有專人填坑，對畫面要求高的項目用Unreal。這里還有一篇老外寫的關于Unity和Unreal的文章，建議閱讀：ExtroForgeTheSwitchfromUnity3DtoUnrealEngineAHighLevelDecisionLetmestartoffbysayingthatI(andotherteammembers)arestillHUGEfansofUnity.SeveralofusontheteamhavebeenusingUnitysincev3.Xdays(includingProlicenses)andCONTINUEtouseitforvariousprojects.IfIwasstartingamobileprojecttoday,IwouldstillreachforUnity.WemadeaLOTofprogressonprotypingExtroForgewiththeUnityengine.Hugeswathsofgameplayelementswereengineeredandintegrated.WethrivedwiththerichvarietyofAssetStorepackagesavailabletousaswellastheYEARSofonlineposts,blogsandtutorials.Withatleasttwo15-yearsoftwareengineeringprofessionalsontheteam,wewereefficientandproficientunderUnity.image08Thefirstiterationwaslessthanimpressive.Extremelylimited(missing?)documentationandoddball(buggy?flaky?)performance.Simplereplicationofananimatedmodel(location/rotation)waseithernon-functionalorsuper-laggy.Weexperimented.Wereadforumposts.Wewaited.TherewerenoofficialUnitytutorials.SomeofthepeoplethatWEREmakingtutorialvideosthatwefollowedactuallygaveupanddecidedtowaituntilfuturereleases.ThentheUnityroadmapwaspublished.WiththeimplementationofthestandalonesimulationserverpushedouttoMarchof2016(plussomeotherelementsundefined),wedecidedtolookatotheroptions.WhatapleasantshockitwastofireupUnrealforthefirsttimewithastarterprojectandseethatlittlesidemenunexttothe“Play”buttonthatallowedyoutoauto-startnotjustadedicatedserver,butalsoasmany‘a(chǎn)dditional'playerclientsasyouwantedto.Itwasmultiplayernirvana.NotethatthiswasnotSOLELYadecisionbasedonmultiplayerfunctionalitybuiltintotheengine.Wehavestruggledforsometimetogettheworld/terrain/foliage/watertolookthewaywewanted.OurTeam/Studioleadwhowasresponsibleforthelookandfeeldecidedtolookatsomeothergameenginestoseehowquicklyhecouldachievethedesiredresults(ourUnityresultseitherlookedtoocartoonishortoo“claylike”).image09C#versusC++versusBlueprints...ohmy.Yeah-notsomuch.image02Oneseniorteammemberhadalreadystartedwiringupsomeblueprintfunctionality-addingtotheskeletonfirstpersoncharacterBPthatwastiedtotheC++classesIhadbeenworkingon.Creatinglittleboxes.dragginglittlewires..allthecolors!!!Iwasfascinated.Mostofitwasinput/controlsrelatedaswellasGUI/UIstuff-elementsIfiguredwereprobablythebestuseforBlueprints.IstartedmyforayintoblueprintsmyselfwasforMateriallogic.IwasAMAZEDatthestuffwecouldeasilydoinsecondsinamaterialblueprintthatwouldhavetaken..DAYSwritingshadercodeinUnity.Itwaseasy,itwasfast,anditwas(dareIsayit)satisfyinglyFUN.WhilemycoderemainedfirmlyinC++land,weslowlylearnedtoexposevariablesfromtheC++sidesotheycouldbeaccessedfromtheseinput/UIblueprintsasneed(stillhaven'tdeterminedifyoucanaccessaBPvariable/functionfromC++side-butitlookslikeitispainful).IlearnedthatIcouldcreatemycriticalsettingsandinitializearraysofimportantgameelementsinC++(whereitwassafeinanon-binary-corruptiblefile)andexposeitintobeusedasnecessaryinBlueprints.Sortof.Sointerestinglyenough..enumsarenowthebaneofmyexistence.Iloveenums.BeenahugefansincebeforethedawnoftimeandhaveusedthemineveryhighlevellanguagesinceIwasaweeengineer.AssetManagementUnityassetmanagementisaverymaturebeast.Dragafileintotheeditor,copyafiletotheAssetsfolder-itjustworked.Moveassetsaroundtodifferentdirectories-justdraganddrop.Thepackageimport/exportfunctionality(someflakydeterminationofdependenciesaside)wastopnotch.Therewereevenenginefunctionsexposed(througheditorscripts)thatallowedyoutocodeallsortsofneato-whizbangcustomlogictomanageyourimage05resources.OurexperienceswithUnreal,howeverweresomewhatpainful.Someofthiswasduetoignorance/inexperienceonourpart-butsomeisstillamystery.Tryingtomigratecontentfromoneprojecttoanother-withdifferentdirectorystructuresprovidedmanywastedhours.Tryingtomigrate(usingthetoolsUnrealprovided)BlueprintsbasedonC++classeswasanunmitigateddisaster.C++classescan'tbemigrated-youhavetocopyonyourown-butshouldyouneedtochangeclassnames(wemigratedfromaprojectwherethewewantedtorenametheautogeneratedcharactercontrollerclasses)themigratedblueprintsarepermanentlycrippleddotoun-changeablereferencestotheoriginalclass.Movingcontent(in-editor)betweenfolderswasalsoaseverepainpoint-Unrealwouldexplicitlyleavecopiesoffilesbehindoremptysubfoldersandallsortsofreferenceswouldgetbroken(someun-fixable).Wegotburnedsomuchbythatlastissue,wesimplytryNOTtomovecontentaround-beingextremelycarefulwhereweplaceitemsfromtheverybeginning.Tobefair,Unity'scritical‘a(chǎn)ssetdatabase'COULDgetcorruptedandwhenitdid,youwereinforaloongperiodofre-importingalltheassets.ButUnitydidthisallautomatically(detectingitsowncorruptionandfixingitself)-whereasanydetectionofissuesorfixingisdonemanuallyinUnreal.AsfarastheUnityAssetStoreversustheUnrealMarketplaceisconcerned-it'ssimplyamatterofmaturity.Unityhashadyearstobuildupalargeandthrivingstorefilledwithbothfree/inexpensiveandpricyassets(ofvaryingquality).AsanauthorofseveralUnitystoreassets,Iwashappywiththecontentcreationandsellingprocess(andmostimportantlypayout).FindingandimportingnewcontentinUnitywasfairlypainless.TheUnrealmarketplaceismostassuredlysmallerMuchsmaller.Tinyeven.Andthe‘a(chǎn)verage'priceforcontentishigher.Nodoubtaboutit.We'vehadnoexperienceyetwithselling(orevenbuying)assetsonthestore,usinginternallycreatedassetsorstartercontentasnecessary.ProceduralmeshmanipulationUnityprovidedtheabilitytomanipulatemeshdata(creatingfromscratchormanipulatingafterthefact)outofthebox.Vertices,vertexcolors,Uvs-itwasallaccessibleandwelldocumented.Overtheyears,Iuseditforcountlessreasons-terraindeformation,meshdestruction/fracturing,andinExtroForge,ourvoxelconstructionenginerequiredit.Itworkedwell,itwasfastanditwasubiquitous.LightingUnrealaddsanincrediblenumberofopenworldlightingtoolstoourarsenal.Yes,UnityrolledoutwithrealtimeglobalilluminationviatheEnlightenengine,butit'sstilllimitedforanopenworldwherestructuresarebeingaddedandremovedallthetime.Whatwereallybenefitedfromwasthedistancefieldambientocclusion,andtherealtimeindirectlightingvialightpropagationvolumes.Lookingintothedistance,thingsinUnitytendedtolookflat.Adistantmountainshouldcastashadowonthevalleybelow,butwithUnitywejustcouldn'tachievethatwithoutaninsaneshadowdistance.HighresScreenshot00218UnrealEnginehadasolutionforthatthat.Distancefieldshadowsandambientocclusionaredesignedtoshadefarawaythingsinanapproximatedkindofwaythatlooksperfectfromfaraway.Wereallywereabletogetthelushandwell-lit/wellshadedworldthatwewantedtowithUnrealEngine.Withlightpropagationvolumes,wewereabletocreateitemswithemissivematerialsthatwouldcastlightontonearbygeometry.Theresultinglookisfantastic.Again-thisislistedas‘experimental'(wehadtomakeasettingintheenginepropertyfilestoenableit),butsofar-sogood!OpenWorldToolsHighresScreenshot00280MiscellaneousFeaturesAndFunctionsOnefinalthing...image07IhavebeenonthereceivingendofseveralcriticalbugsinUnitythatpreventedsomemo