View Space From gl_FragCoord - Game Development Stack ...

Space & Sound? Defying Physics? 1 · Why are normal maps in tangent space but not in normal space? 14 · Why is clip space always referred to as " ... 2022DeveloperSurveyisopen!Takesurvey. GameDevelopmentStackExchangeisaquestionandanswersiteforprofessionalandindependentgamedevelopers.Itonlytakesaminutetosignup. Signuptojointhiscommunity Anybodycanaskaquestion Anybodycananswer Thebestanswersarevotedupandrisetothetop Home Public Questions Tags Users Companies Unanswered Teams StackOverflowforTeams –Startcollaboratingandsharingorganizationalknowledge. CreateafreeTeam WhyTeams? Teams CreatefreeTeam Teams Q&Aforwork Connectandshareknowledgewithinasinglelocationthatisstructuredandeasytosearch. Learnmore ViewSpaceFromgl_FragCoord AskQuestion Asked 3yearsago Modified 3monthsago Viewed 227times 0 \$\begingroup\$ TryingtogettheexamplecodeforCalcEyeFromWindow()(firstoneonthepage)toworkinWebGL,buthavingnoluck. Paireddownthecodetothefollowingwithsomeexplicitvaluesjustincasesomethingisamisswithparameterpassing.Visualizingtheoutputonasphereofunitradius,centeredintheviewand3unitsfromthecamera.Usingstep()intheoutputtoprovidesharpcolortransitionsonthesphere. Thecurrentoutputisblack.IfIsetthestepto0forXandY,thetransitionsforXandYarecenteredonthesphere,soitwouldseemthattheproblemisatleastinpartduetothecalculationofclipPos.w. Vertexshader: precisionhighpfloat; attributevec3a_position; uniformmat4u_modelMatrix; uniformmat4u_viewMatrix; uniformmat4u_projectionMatrix; voidmain() { gl_Position=u_projectionMatrix*u_viewMatrix*u_modelMatrix*vec4(a_position,1.0); } Fragmentshader: precisionhighpfloat; uniformmat4u_inverseProjectionMatrix; uniformmat4u_projectionMatrix; vec3CalcEyeFromWindow(void) { vec3ndcPos; //Hardcodewindow-spacepositionatgl_FragCoord //Hardcodeviewportdimensions ndcPos.xy=(2.0*gl_FragCoord.xy)/vec2(1000,500)-1.; //Hardcodeclippingdepths ndcPos.z=(2.0*gl_FragCoord.z-1.-4.)/(4.-1.); vec4clipPos; clipPos.w=u_projectionMatrix[3][2]/ (ndcPos.z-(u_projectionMatrix[2][2]/u_projectionMatrix[2][3])); clipPos.xyz=ndcPos*clipPos.w; return(u_inverseProjectionMatrix*clipPos).xyz; } voidmain(){ //Steptoclarifyposition gl_FragColor=vec4(step(vec3(.5,.5,2.2),CalcEyeFromWindow()* vec3(1,1,-1)),1.); } webglspaces Share Improvethisquestion Follow askedMay16,2019at16:05 cageyocageyo 1 \$\endgroup\$ Addacomment  |  1Answer 1 Sortedby: Resettodefault Highestscore(default) Datemodified(newestfirst) Datecreated(oldestfirst) 0 \$\begingroup\$ TheproblemwasthatIhadusedtheclipplanedepthswhereIshouldhaveusedthenearandfarvaluesaspassedtoglDepthRange,whichInowknoware0and1bydefault.So,sinceIusethesedefaultvalues,thecalculationofndcPos.zshouldbe: ndcPos.z=(2.0*gl_FragCoord.z-0.0-1.0)/(1.0-0.0); whichcanbesimplifiedto: ndcPos.z=2.0*gl_FragCoord.z-1.0; Share Improvethisanswer Follow answeredMay20,2019at20:34 cageyocageyo 1 \$\endgroup\$ Addacomment  |  Youmustlogintoanswerthisquestion. 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