WebGL Setup and Installation

js. Download it, install it, then open a command prompt / console / terminal window. If you're on Windows the installer will add a special " ... English Français 日本語 한국어 Polski Portuguese Русский 简体中文 TableofContents WebGLFundamentals.org Fix,Fork,Contribute WebGLSetupandInstallation Technicallyyoudon'tneedanythingotherthanawebbrowsertodoWebGL development.Gotojsfiddle.netorjsbin.com orcodepen.ioandjuststartapplyingthelessonshere. Onallofthemyoucanreferenceexternalscriptsbyaddinga tagpairifyouwanttouseexternalscripts. Still,therearelimits.WebGLhasstrongerrestrictionsthanCanvas2Dforloadingimages whichmeansyoucan'teasilyaccessimagesfromaroundthewebforyourWebGLwork. Ontopofthatit'sjustfastertoworkwitheverythinglocal. Let'sassumeyouwanttorunandeditthesamplesonthissite.Thefirstthingyoushould doisdownloadthesite.Youcandownloadithere. Unzipthefilesintosomefolder. UsingasmallsimpleeasyWebServer Nextupyoushouldinstallasmallwebserver.Iknow"webserver"soundsscarybutthetruthisweb serversareactuallyextremelysimple. Here'saverysimpleonewithaninterfacecalledServez. Justpointitatthefolderwhereyouunzippedthefiles,click"Start",thengoto inyourbrowserhttp://localhost:8080/webgl/andchoose asample. Ifyoupreferthecommandline,anotherwayistousenode.js. Downloadit,installit,thenopenacommandprompt/console/terminalwindow.Ifyou'reonWindowstheinstaller willaddaspecial"NodeCommandPrompt"sousethat. Theninstallservezbytyping npm-ginstallservez Ifyou'reonOSXuse sudonpm-ginstallservez Onceyou'vedonethattype servezpath/to/folder/where/you/unzipped/files Itshouldprintsomethinglike Theninyourbrowsergotohttp://localhost:8080/webgl/. Ifyoudon'tspecifyapaththenservezwillservethecurrentfolder. UsingyourBrowsersDeveloperTools Mostbrowserhaveextensivedevelopertoolsbuiltin. DocsforChrome'sarehere, Firefox'sarehere. Learnhowtousethem.IfnothingelsealwayschecktheJavaScriptconsole.Ifthereisanissueitwilloftenhave anerrormessage.Readtheerrormessagecloselyandyoushouldgetacluewheretheissueis. WebGLLint Hereisascripttocheckforseveral webglerrors.Justaddthistoyourpagebeforeyourotherscripts andyourprogramwillthrowanexceptionifitgetsaWebGLerrorandifyou'relucky printmoreinfo. Youcanalsoaddnamestoyourwebglresources (buffer,textures,shaders,programs,...)sothatwhenyougetanerrormessageit willincludethenamesoftheresourcesrelevanttotheerror. Extensions TherearevariousWebGLInspectors. Here'soneforChromeandFirefox. Note:READTHEDOCS! Theextensionversionofspector.jscapturesframes.Whatthisismeansisitonly worksifyourWebGLappsuccessfullyinitializesitselfandthenrendersina requestAnimationFrameloop.Youclickthe"record"buttonanditcaptures alltheWebGLAPIcallsforone"frame". Thismeanswithoutsomeworkitwon'thelpyoufindissuesduringinitialization. Toworkaroundthatthereare2methods. Useitasalibrary,notasanextension. Seethedocs.Thiswayyoucantellit"CapturetheWebGLAPIcommandsnow!" Changeyourappsothatitdoesn'tstartuntilyouclickabutton. Thiswayyoucangototheextensionandpick"record"andthenstartyour app.Ifyourappdoesn'tanimatethenjustaddafewfakeframes.Example: start functionmain(){ //GetAWebGLcontext /**@type{HTMLCanvasElement}*/ constcanvas=document.querySelector("#canvas"); constgl=canvas.getContext("webgl"); if(!gl){ return; } conststartElem=document.querySelector('button'); startElem.addEventListener('click',start,{once:true}); functionstart(){ //runtheinitializationinrAFsincespectoronlycapturesinsiderAFevents requestAnimationFrame(()=>{ //doalltheinitialization init(gl); }); //makesomoreframessospectorhassomethingtolookat. requestAnimationFrame(()=>{}); requestAnimationFrame(()=>{}); requestAnimationFrame(()=>{}); } } main(); Nowyoucanclick"record"inthespector.jsextension,thenclick"start"inyourpage andspectorwillrecordyourinitialization. Safarialsohasasimilarbuiltinfeaturethathassimilarissueswithsimilarworkarounds. WhenIuseahelperlikethisI'lloftenclickonadrawcall,andchecktheuniforms.IfIseeabunchofNaN(NaN=NotaNumber)thenIcanusuallytrackdownthecodethatsetthatuniformandfindthebug. InspecttheCode Alsoalwaysrememberyoucaninspectthecode.Youcanusuallyjustpickviewsource Evenifyoucan'trightclickapageorifthesourceisinaseparatefile youcanalwaysviewthesourceinthedevtools GetStarted Hopefullythathelpsyougetstarted.Nowbacktothelessons. English Français 日本語 한국어 Polski Portuguese Русский 简体中文 Fundamentals Fundamentals HowItWorks ShadersandGLSL WebGLStateDiagram ImageProcessing ImageProcessing ImageProcessingContinued 2Dtranslation,rotation,scale,matrixmath 2DTranslation 2DRotation 2DScale 2DMatrices 3D Orthographic3D 3DPerspective 3DCameras Lighting DirectionalLighting PointLighting SpotLighting StructureandOrganization LessCode,MoreFun DrawingMultipleThings SceneGraphs Geometry Geometry-Lathe Loading.objfiles Loading.objw.mtlfiles Textures Textures DataTextures Using2orMoreTextures CrossOriginImages PerspectiveCorrectTextureMapping PlanarandPerspectiveProjectionMapping RenderingToATexture RendertoTexture Shadows Shadows Techniques 2D 2D-DrawImage 2D-MatrixStack Sprites 3D Cubemaps Environmentmaps Skyboxes Skinning Fog Picking(clickingonstuff) Text Text-HTML Text-Canvas2D Text-UsingaTexture Text-UsingaGlyphTexture Textures RampTextures(ToonShading) GPGPU GPGPU Tips SmallestPrograms DrawingWithoutData Shadertoy PullingVertices Optimization IndexedVertices(gl.drawElements) InstancedDrawing Misc SetupAndInstallation Boilerplate ResizingtheCanvas Animation Points,Lines,andTriangles MultipleViews,MultipleCanvases VisualizingtheCamera WebGLandAlpha 2Dvs3Dlibraries Anti-Patterns WebGLMatricesvsMathMatrices PrecisionIssues Takingascreenshot PreventtheCanvasBeingCleared GetKeyboardInputFromaCanvas UseWebGLasBackgroundinHTML CrossPlatformIssues QuestionsandAnswers Reference Attributes TextureUnits Framebuffers readPixels References HelperAPIDocs TWGL,AtinyWebGLhelperlibrary github Questions?Askonstackoverflow. Issue/Bug?Createanissueongithub. Use

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