kopia lustrzana https://github.com/robhawkes/vizicities
269 wiersze
8.2 KiB
JavaScript
Executable File
269 wiersze
8.2 KiB
JavaScript
Executable File
// jscs:disable
|
|
/*eslint eqeqeq:0*/
|
|
|
|
/**
|
|
* @author zz85 / https://github.com/zz85
|
|
*
|
|
* Based on 'A Practical Analytic Model for Daylight'
|
|
* aka The Preetham Model, the de facto standard analytic skydome model
|
|
* http://www.cs.utah.edu/~shirley/papers/sunsky/sunsky.pdf
|
|
*
|
|
* First implemented by Simon Wallner
|
|
* http://www.simonwallner.at/projects/atmospheric-scattering
|
|
*
|
|
* Improved by Martin Upitis
|
|
* http://blenderartists.org/forum/showthread.php?245954-preethams-sky-impementation-HDR
|
|
*
|
|
* Three.js integration by zz85 http://twitter.com/blurspline
|
|
*/
|
|
|
|
import THREE from 'three';
|
|
|
|
THREE.ShaderLib[ 'sky' ] = {
|
|
|
|
uniforms: {
|
|
|
|
luminance: { type: 'f', value: 1 },
|
|
turbidity: { type: 'f', value: 2 },
|
|
reileigh: { type: 'f', value: 1 },
|
|
mieCoefficient: { type: 'f', value: 0.005 },
|
|
mieDirectionalG: { type: 'f', value: 0.8 },
|
|
sunPosition: { type: 'v3', value: new THREE.Vector3() }
|
|
|
|
},
|
|
|
|
vertexShader: [
|
|
|
|
'varying vec3 vWorldPosition;',
|
|
|
|
'void main() {',
|
|
|
|
'vec4 worldPosition = modelMatrix * vec4( position, 1.0 );',
|
|
'vWorldPosition = worldPosition.xyz;',
|
|
|
|
'gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',
|
|
|
|
'}',
|
|
|
|
].join( '\n' ),
|
|
|
|
fragmentShader: [
|
|
|
|
'uniform sampler2D skySampler;',
|
|
'uniform vec3 sunPosition;',
|
|
'varying vec3 vWorldPosition;',
|
|
|
|
'vec3 cameraPos = vec3(0., 0., 0.);',
|
|
'// uniform sampler2D sDiffuse;',
|
|
'// const float turbidity = 10.0; //',
|
|
'// const float reileigh = 2.; //',
|
|
'// const float luminance = 1.0; //',
|
|
'// const float mieCoefficient = 0.005;',
|
|
'// const float mieDirectionalG = 0.8;',
|
|
|
|
'uniform float luminance;',
|
|
'uniform float turbidity;',
|
|
'uniform float reileigh;',
|
|
'uniform float mieCoefficient;',
|
|
'uniform float mieDirectionalG;',
|
|
|
|
'// constants for atmospheric scattering',
|
|
'const float e = 2.71828182845904523536028747135266249775724709369995957;',
|
|
'const float pi = 3.141592653589793238462643383279502884197169;',
|
|
|
|
'const float n = 1.0003; // refractive index of air',
|
|
'const float N = 2.545E25; // number of molecules per unit volume for air at',
|
|
'// 288.15K and 1013mb (sea level -45 celsius)',
|
|
'const float pn = 0.035; // depolatization factor for standard air',
|
|
|
|
'// wavelength of used primaries, according to preetham',
|
|
'const vec3 lambda = vec3(680E-9, 550E-9, 450E-9);',
|
|
|
|
'// mie stuff',
|
|
'// K coefficient for the primaries',
|
|
'const vec3 K = vec3(0.686, 0.678, 0.666);',
|
|
'const float v = 4.0;',
|
|
|
|
'// 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 EE = 1000.0;',
|
|
'const float sunAngularDiameterCos = 0.999956676946448443553574619906976478926848692873900859324;',
|
|
'// 66 arc seconds -> degrees, and the cosine of that',
|
|
|
|
'// earth shadow hack',
|
|
'const float cutoffAngle = pi/1.95;',
|
|
'const float steepness = 1.5;',
|
|
|
|
|
|
'vec3 totalRayleigh(vec3 lambda)',
|
|
'{',
|
|
'return (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));',
|
|
'}',
|
|
|
|
// 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',
|
|
'vec3 simplifiedRayleigh()',
|
|
'{',
|
|
'return 0.0005 / vec3(94, 40, 18);',
|
|
// return 0.00054532832366 / (3.0 * 2.545E25 * pow(vec3(680E-9, 550E-9, 450E-9), vec3(4.0)) * 6.245);
|
|
'}',
|
|
|
|
'float rayleighPhase(float cosTheta)',
|
|
'{ ',
|
|
'return (3.0 / (16.0*pi)) * (1.0 + pow(cosTheta, 2.0));',
|
|
'// return (1.0 / (3.0*pi)) * (1.0 + pow(cosTheta, 2.0));',
|
|
'// return (3.0 / 4.0) * (1.0 + pow(cosTheta, 2.0));',
|
|
'}',
|
|
|
|
'vec3 totalMie(vec3 lambda, vec3 K, 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 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 sunIntensity(float zenithAngleCos)',
|
|
'{',
|
|
'return EE * max(0.0, 1.0 - exp(-((cutoffAngle - acos(zenithAngleCos))/steepness)));',
|
|
'}',
|
|
|
|
'// float logLuminance(vec3 c)',
|
|
'// {',
|
|
'// return log(c.r * 0.2126 + c.g * 0.7152 + c.b * 0.0722);',
|
|
'// }',
|
|
|
|
'// Filmic ToneMapping http://filmicgames.com/archives/75',
|
|
'float A = 0.15;',
|
|
'float B = 0.50;',
|
|
'float C = 0.10;',
|
|
'float D = 0.20;',
|
|
'float E = 0.02;',
|
|
'float F = 0.30;',
|
|
'float W = 1000.0;',
|
|
|
|
'vec3 Uncharted2Tonemap(vec3 x)',
|
|
'{',
|
|
'return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;',
|
|
'}',
|
|
|
|
|
|
'void main() ',
|
|
'{',
|
|
'float sunfade = 1.0-clamp(1.0-exp((sunPosition.y/450000.0)),0.0,1.0);',
|
|
|
|
'// luminance = 1.0 ;// vWorldPosition.y / 450000. + 0.5; //sunPosition.y / 450000. * 1. + 0.5;',
|
|
|
|
'// gl_FragColor = vec4(sunfade, sunfade, sunfade, 1.0);',
|
|
|
|
'float reileighCoefficient = reileigh - (1.0* (1.0-sunfade));',
|
|
|
|
'vec3 sunDirection = normalize(sunPosition);',
|
|
|
|
'float sunE = sunIntensity(dot(sunDirection, up));',
|
|
|
|
'// extinction (absorbtion + out scattering) ',
|
|
'// rayleigh coefficients',
|
|
|
|
// 'vec3 betaR = totalRayleigh(lambda) * reileighCoefficient;',
|
|
'vec3 betaR = simplifiedRayleigh() * reileighCoefficient;',
|
|
|
|
'// mie coefficients',
|
|
'vec3 betaM = totalMie(lambda, K, turbidity) * mieCoefficient;',
|
|
|
|
'// 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));',
|
|
|
|
|
|
|
|
'// combined extinction factor ',
|
|
'vec3 Fex = exp(-(betaR * sR + betaM * sM));',
|
|
|
|
'// in scattering',
|
|
'float cosTheta = dot(normalize(vWorldPosition - cameraPos), sunDirection);',
|
|
|
|
'float rPhase = rayleighPhase(cosTheta*0.5+0.5);',
|
|
'vec3 betaRTheta = betaR * rPhase;',
|
|
|
|
'float mPhase = hgPhase(cosTheta, mieDirectionalG);',
|
|
'vec3 betaMTheta = betaM * mPhase;',
|
|
|
|
|
|
'vec3 Lin = pow(sunE * ((betaRTheta + betaMTheta) / (betaR + betaM)) * (1.0 - Fex),vec3(1.5));',
|
|
'Lin *= mix(vec3(1.0),pow(sunE * ((betaRTheta + betaMTheta) / (betaR + betaM)) * Fex,vec3(1.0/2.0)),clamp(pow(1.0-dot(up, sunDirection),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 = texture2D(skySampler, uv).rgb+0.1 * Fex;',
|
|
'vec3 L0 = vec3(0.1) * Fex;',
|
|
|
|
'// composition + solar disc',
|
|
'//if (cosTheta > sunAngularDiameterCos)',
|
|
'float sundisk = smoothstep(sunAngularDiameterCos,sunAngularDiameterCos+0.00002,cosTheta);',
|
|
'// if (normalize(vWorldPosition - cameraPos).y>0.0)',
|
|
'L0 += (sunE * 19000.0 * Fex)*sundisk;',
|
|
|
|
|
|
'vec3 whiteScale = 1.0/Uncharted2Tonemap(vec3(W));',
|
|
|
|
'vec3 texColor = (Lin+L0); ',
|
|
'texColor *= 0.04 ;',
|
|
'texColor += vec3(0.0,0.001,0.0025)*0.3;',
|
|
|
|
'float g_fMaxLuminance = 1.0;',
|
|
'float fLumScaled = 0.1 / luminance; ',
|
|
'float fLumCompressed = (fLumScaled * (1.0 + (fLumScaled / (g_fMaxLuminance * g_fMaxLuminance)))) / (1.0 + fLumScaled); ',
|
|
|
|
'float ExposureBias = fLumCompressed;',
|
|
|
|
'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*sunfade))));',
|
|
|
|
|
|
'gl_FragColor.rgb = retColor;',
|
|
|
|
'gl_FragColor.a = 1.0;',
|
|
'}',
|
|
|
|
].join( '\n' )
|
|
|
|
};
|
|
|
|
var Sky = function () {
|
|
|
|
var skyShader = THREE.ShaderLib[ 'sky' ];
|
|
var skyUniforms = THREE.UniformsUtils.clone( skyShader.uniforms );
|
|
|
|
var skyMat = new THREE.ShaderMaterial( {
|
|
fragmentShader: skyShader.fragmentShader,
|
|
vertexShader: skyShader.vertexShader,
|
|
uniforms: skyUniforms,
|
|
side: THREE.BackSide
|
|
} );
|
|
|
|
var skyGeo = new THREE.SphereBufferGeometry( 450000, 32, 15 );
|
|
var skyMesh = new THREE.Mesh( skyGeo, skyMat );
|
|
|
|
|
|
// Expose variables
|
|
this.mesh = skyMesh;
|
|
this.uniforms = skyUniforms;
|
|
|
|
};
|
|
|
|
export default Sky;
|