diff --git a/examples/js/SkyShader.js b/examples/js/SkyShader.js index 9f519c614bd7034e7e010e506381f984c736b771..a12fa2c24c56dc9f342d819ec274ab8c26e99dd6 100644 --- a/examples/js/SkyShader.js +++ b/examples/js/SkyShader.js @@ -41,39 +41,41 @@ THREE.ShaderLib[ 'sky' ] = { "varying vec3 vBetaM;", "varying float vSunE;", - "const vec3 up = vec3(0.0, 1.0, 0.0);", + "const vec3 up = vec3( 0.0, 1.0, 0.0 );", // constants for atmospheric scattering "const float e = 2.71828182845904523536028747135266249775724709369995957;", "const float pi = 3.141592653589793238462643383279502884197169;", + // wavelength of used primaries, according to preetham + "const vec3 lambda = vec3( 680E-9, 550E-9, 450E-9 );", + // this pre-calcuation replaces older TotalRayleigh(vec3 lambda) function: + // (8.0 * pow(pi, 3.0) * pow(pow(n, 2.0) - 1.0, 2.0) * (6.0 + 3.0 * pn)) / (3.0 * N * pow(lambda, vec3(4.0)) * (6.0 - 7.0 * pn)) + "const vec3 totalRayleigh = vec3( 5.804542996261093E-6, 1.3562911419845635E-5, 3.0265902468824876E-5 );", + // mie stuff // K coefficient for the primaries "const float v = 4.0;", - "const vec3 K = vec3(0.686, 0.678, 0.666);", - - // see http://blenderartists.org/forum/showthread.php?321110-Shaders-and-Skybox-madness - // A simplied version of the total Reayleigh scattering to works on browsers that use ANGLE - "const vec3 simplifiedRayleigh = 0.0005 / vec3(94, 40, 18);", - - // wavelength of used primaries, according to preetham - "const vec3 lambda = vec3(680E-9, 550E-9, 450E-9);", + "const vec3 K = vec3( 0.686, 0.678, 0.666 );", + // MieConst = pi * pow( ( 2.0 * pi ) / lambda, vec3( v - 2.0 ) ) * K + "const vec3 MieConst = vec3( 1.8399918514433978E14, 2.7798023919660528E14, 4.0790479543861094E14 );", // earth shadow hack - "const float cutoffAngle = pi/1.95;", + // cutoffAngle = pi / 1.95; + "const float cutoffAngle = 1.6110731556870734;", "const float steepness = 1.5;", "const float EE = 1000.0;", - "float sunIntensity(float zenithAngleCos)", + "float sunIntensity( float zenithAngleCos )", "{", - "zenithAngleCos = clamp(zenithAngleCos, -1.0, 1.0);", - "return EE * max(0.0, 1.0 - pow(e, -((cutoffAngle - acos(zenithAngleCos))/steepness)));", + "zenithAngleCos = clamp( zenithAngleCos, -1.0, 1.0 );", + "return EE * max( 0.0, 1.0 - pow( e, -( ( cutoffAngle - acos( zenithAngleCos ) ) / steepness ) ) );", "}", - "vec3 totalMie(vec3 lambda, float T)", + "vec3 totalMie( float T )", "{", - "float c = (0.2 * T ) * 10E-18;", - "return 0.434 * c * pi * pow((2.0 * pi) / lambda, vec3(v - 2.0)) * K;", + "float c = ( 0.2 * T ) * 10E-18;", + "return 0.434 * c * MieConst;", "}", "void main() {", @@ -83,20 +85,20 @@ THREE.ShaderLib[ 'sky' ] = { "gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", - "vSunDirection = normalize(sunPosition);", + "vSunDirection = normalize( sunPosition );", - "vSunE = sunIntensity(dot(vSunDirection, up));", + "vSunE = sunIntensity( dot( vSunDirection, up ) );", - "vSunfade = 1.0-clamp(1.0-exp((sunPosition.y/450000.0)),0.0,1.0);", + "vSunfade = 1.0 - clamp( 1.0 - exp( ( sunPosition.y / 450000.0 ) ), 0.0, 1.0 );", - "float rayleighCoefficient = rayleigh - (1.0 * (1.0-vSunfade));", + "float rayleighCoefficient = rayleigh - ( 1.0 * ( 1.0 - vSunfade ) );", // extinction (absorbtion + out scattering) // rayleigh coefficients - "vBetaR = simplifiedRayleigh * rayleighCoefficient;", + "vBetaR = totalRayleigh * rayleighCoefficient;", // mie coefficients - "vBetaM = totalMie(lambda, turbidity) * mieCoefficient;", + "vBetaM = totalMie( turbidity ) * mieCoefficient;", "}" @@ -114,7 +116,7 @@ THREE.ShaderLib[ 'sky' ] = { "uniform float luminance;", "uniform float mieDirectionalG;", - "const vec3 cameraPos = vec3(0., 0., 0.);", + "const vec3 cameraPos = vec3( 0.0, 0.0, 0.0 );", // constants for atmospheric scattering "const float pi = 3.141592653589793238462643383279502884197169;", @@ -126,19 +128,25 @@ THREE.ShaderLib[ 'sky' ] = { // optical length at zenith for molecules "const float rayleighZenithLength = 8.4E3;", "const float mieZenithLength = 1.25E3;", - "const vec3 up = vec3(0.0, 1.0, 0.0);", - - "const float sunAngularDiameterCos = 0.999956676946448443553574619906976478926848692873900859324;", + "const vec3 up = vec3( 0.0, 1.0, 0.0 );", // 66 arc seconds -> degrees, and the cosine of that + "const float sunAngularDiameterCos = 0.999956676946448443553574619906976478926848692873900859324;", + + // 3.0 / ( 16.0 * pi ) + "const float THREE_OVER_SIXTEENPI = 0.05968310365946075;", + // 1.0 / ( 4.0 * pi ) + "const float ONE_OVER_FOURPI = 0.07957747154594767;", - "float rayleighPhase(float cosTheta)", + "float rayleighPhase( float cosTheta )", "{", - "return (3.0 / (16.0*pi)) * (1.0 + pow(cosTheta, 2.0));", + "return THREE_OVER_SIXTEENPI * ( 1.0 + pow( cosTheta, 2.0 ) );", "}", - "float hgPhase(float cosTheta, float g)", + "float hgPhase( float cosTheta, float g )", "{", - "return (1.0 / (4.0*pi)) * ((1.0 - pow(g, 2.0)) / pow(1.0 - 2.0*g*cosTheta + pow(g, 2.0), 1.5));", + "float g2 = pow( g, 2.0 );", + "float inverse = 1.0 / pow( 1.0 - 2.0 * g * cosTheta + g2, 1.5 );", + "return ONE_OVER_FOURPI * ( ( 1.0 - g2 ) * inverse );", "}", // Filmic ToneMapping http://filmicgames.com/archives/75 @@ -151,9 +159,9 @@ THREE.ShaderLib[ 'sky' ] = { "const float whiteScale = 1.0748724675633854;", // 1.0 / Uncharted2Tonemap(1000.0) - "vec3 Uncharted2Tonemap(vec3 x)", + "vec3 Uncharted2Tonemap( vec3 x )", "{", - "return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;", + "return ( ( x * ( A * x + C * B ) + D * E ) / ( x * ( A * x + B ) + D * F ) ) - E / F;", "}", @@ -161,42 +169,43 @@ THREE.ShaderLib[ 'sky' ] = { "{", // optical length // cutoff angle at 90 to avoid singularity in next formula. - "float zenithAngle = acos(max(0.0, dot(up, normalize(vWorldPosition - cameraPos))));", - "float sR = rayleighZenithLength / (cos(zenithAngle) + 0.15 * pow(93.885 - ((zenithAngle * 180.0) / pi), -1.253));", - "float sM = mieZenithLength / (cos(zenithAngle) + 0.15 * pow(93.885 - ((zenithAngle * 180.0) / pi), -1.253));", + "float zenithAngle = acos( max( 0.0, dot( up, normalize( vWorldPosition - cameraPos ) ) ) );", + "float inverse = 1.0 / ( cos( zenithAngle ) + 0.15 * pow( 93.885 - ( ( zenithAngle * 180.0 ) / pi ), -1.253 ) );", + "float sR = rayleighZenithLength * inverse;", + "float sM = mieZenithLength * inverse;", // combined extinction factor - "vec3 Fex = exp(-(vBetaR * sR + vBetaM * sM));", + "vec3 Fex = exp( -( vBetaR * sR + vBetaM * sM ) );", // in scattering - "float cosTheta = dot(normalize(vWorldPosition - cameraPos), vSunDirection);", + "float cosTheta = dot( normalize( vWorldPosition - cameraPos ), vSunDirection );", - "float rPhase = rayleighPhase(cosTheta*0.5+0.5);", + "float rPhase = rayleighPhase( cosTheta * 0.5 + 0.5 );", "vec3 betaRTheta = vBetaR * rPhase;", - "float mPhase = hgPhase(cosTheta, mieDirectionalG);", + "float mPhase = hgPhase( cosTheta, mieDirectionalG );", "vec3 betaMTheta = vBetaM * mPhase;", - "vec3 Lin = pow(vSunE * ((betaRTheta + betaMTheta) / (vBetaR + vBetaM)) * (1.0 - Fex),vec3(1.5));", - "Lin *= mix(vec3(1.0),pow(vSunE * ((betaRTheta + betaMTheta) / (vBetaR + vBetaM)) * Fex,vec3(1.0/2.0)),clamp(pow(1.0-dot(up, vSunDirection),5.0),0.0,1.0));", + "vec3 Lin = pow( vSunE * ( ( betaRTheta + betaMTheta ) / ( vBetaR + vBetaM ) ) * ( 1.0 - Fex ), vec3( 1.5 ) );", + "Lin *= mix( vec3( 1.0 ), pow( vSunE * ( ( betaRTheta + betaMTheta ) / ( vBetaR + vBetaM ) ) * Fex, vec3( 1.0 / 2.0 ) ), clamp( pow( 1.0 - dot( up, vSunDirection ), 5.0 ), 0.0, 1.0 ) );", //nightsky - "vec3 direction = normalize(vWorldPosition - cameraPos);", - "float theta = acos(direction.y); // elevation --> y-axis, [-pi/2, pi/2]", - "float phi = atan(direction.z, direction.x); // azimuth --> x-axis [-pi/2, pi/2]", - "vec2 uv = vec2(phi, theta) / vec2(2.0*pi, pi) + vec2(0.5, 0.0);", - "vec3 L0 = vec3(0.1) * Fex;", + "vec3 direction = normalize( vWorldPosition - cameraPos );", + "float theta = acos( direction.y ); // elevation --> y-axis, [-pi/2, pi/2]", + "float phi = atan( direction.z, direction.x ); // azimuth --> x-axis [-pi/2, pi/2]", + "vec2 uv = vec2( phi, theta ) / vec2( 2.0 * pi, pi ) + vec2( 0.5, 0.0 );", + "vec3 L0 = vec3( 0.1 ) * Fex;", // composition + solar disc - "float sundisk = smoothstep(sunAngularDiameterCos,sunAngularDiameterCos+0.00002,cosTheta);", - "L0 += (vSunE * 19000.0 * Fex)*sundisk;", + "float sundisk = smoothstep( sunAngularDiameterCos, sunAngularDiameterCos + 0.00002, cosTheta );", + "L0 += ( vSunE * 19000.0 * Fex ) * sundisk;", - "vec3 texColor = (Lin+L0) * 0.04 + vec3(0.0, 0.0003, 0.00075);", + "vec3 texColor = ( Lin + L0 ) * 0.04 + vec3( 0.0, 0.0003, 0.00075 );", - "vec3 curr = Uncharted2Tonemap((log2(2.0/pow(luminance,4.0)))*texColor);", - "vec3 color = curr*whiteScale;", + "vec3 curr = Uncharted2Tonemap( ( log2( 2.0 / pow( luminance, 4.0 ) ) ) * texColor );", + "vec3 color = curr * whiteScale;", - "vec3 retColor = pow(color,vec3(1.0/(1.2+(1.2*vSunfade))));", + "vec3 retColor = pow( color, vec3( 1.0 / ( 1.2 + ( 1.2 * vSunfade ) ) ) );", "gl_FragColor.rgb = retColor;",