three-shaders
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three-shaders - a library of shaders included with Three.js library
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JavaScript
// Author: Aleksandr Albert
// Website: www.routter.co.tt
// Description: A deep water ocean shader set
// based on an implementation of a Tessendorf Waves
// originally presented by David Li ( www.david.li/waves )
// The general method is to apply shaders to simulation Framebuffers
// and then sample these framebuffers when rendering the ocean mesh
// The set uses 7 shaders:
// -- Simulation shaders
// [1] ocean_sim_vertex -> Vertex shader used to set up a 2x2 simulation plane centered at (0,0)
// [2] ocean_subtransform -> Fragment shader used to subtransform the mesh (generates the displacement map)
// [3] ocean_initial_spectrum -> Fragment shader used to set intitial wave frequency at a texel coordinate
// [4] ocean_phase -> Fragment shader used to set wave phase at a texel coordinate
// [5] ocean_spectrum -> Fragment shader used to set current wave frequency at a texel coordinate
// [6] ocean_normal -> Fragment shader used to set face normals at a texel coordinate
// -- Rendering Shader
// [7] ocean_main -> Vertex and Fragment shader used to create the final render
var THREE = require('three');
var OceanShaderLib = [];
OceanShaderLib['ocean_sim_vertex'] = function() {
return {
vertexShader: `
varying vec2 vUV;
void main (void) {
vUV = position.xy * 0.5 + 0.5;
gl_Position = vec4(position, 1.0 );
}
`
}
};
OceanShaderLib['ocean_subtransform'] = function() {
return {
uniforms: {
u_input: { value: null },
u_transformSize: { value: 512.0 },
u_subtransformSize: { value: 250.0 }
},
fragmentShader: `
//GPU FFT using a Stockham formulation
precision highp float;
uniform sampler2D u_input;
uniform float u_transformSize;
uniform float u_subtransformSize;
varying vec2 vUV;
vec2 multiplyComplex (vec2 a, vec2 b) {
return vec2(a[0] * b[0] - a[1] * b[1], a[1] * b[0] + a[0] * b[1]);
}
void main (void) {
float index = vUV.x * u_transformSize - 0.5;
float index = vUV.y * u_transformSize - 0.5;
float evenIndex = floor(index / u_subtransformSize) * (u_subtransformSize * 0.5) + mod(index, u_subtransformSize * 0.5);
//transform two complex sequences simultaneously
vec4 even = texture2D(u_input, vec2(evenIndex + 0.5, gl_FragCoord.y) / u_transformSize).rgba;
vec4 odd = texture2D(u_input, vec2(evenIndex + u_transformSize * 0.5 + 0.5, gl_FragCoord.y) / u_transformSize).rgba;
vec4 even = texture2D(u_input, vec2(gl_FragCoord.x, evenIndex + 0.5) / u_transformSize).rgba;
vec4 odd = texture2D(u_input, vec2(gl_FragCoord.x, evenIndex + u_transformSize * 0.5 + 0.5) / u_transformSize).rgba;
float twiddleArgument = -2.0 * PI * (index / u_subtransformSize);
vec2 twiddle = vec2(cos(twiddleArgument), sin(twiddleArgument));
vec2 outputA = even.xy + multiplyComplex(twiddle, odd.xy);
vec2 outputB = even.zw + multiplyComplex(twiddle, odd.zw);
gl_FragColor = vec4(outputA, outputB);
}
`
}
};
OceanShaderLib['ocean_initial_spectrum'] = function() {
return {
uniforms: {
u_wind: { value: new THREE.Vector2( 10.0, 10.0 ) },
u_resolution: { value: 512.0 },
u_size: { value: 250.0 }
},
fragmentShader: `
precision highp float;
const float G = 9.81;
const float KM = 370.0;
const float CM = 0.23;
uniform vec2 u_wind;
uniform float u_resolution;
uniform float u_size;
float omega (float k) {
return sqrt(G * k * (1.0 + pow2(k / KM)));
}
float tanh (float x) {
return (1.0 - exp(-2.0 * x)) / (1.0 + exp(-2.0 * x));
}
void main (void) {
vec2 coordinates = gl_FragCoord.xy - 0.5;
float n = (coordinates.x < u_resolution * 0.5) ? coordinates.x : coordinates.x - u_resolution;
float m = (coordinates.y < u_resolution * 0.5) ? coordinates.y : coordinates.y - u_resolution;
vec2 K = (2.0 * PI * vec2(n, m)) / u_size;
float k = length(K);
float l_wind = length(u_wind);
float Omega = 0.84;
float kp = G * pow2(Omega / l_wind);
float c = omega(k) / k;
float cp = omega(kp) / kp;
float Lpm = exp(-1.25 * pow2(kp / k));
float gamma = 1.7;
float sigma = 0.08 * (1.0 + 4.0 * pow(Omega, -3.0));
float Gamma = exp(-pow2(sqrt(k / kp) - 1.0) / 2.0 * pow2(sigma));
float Jp = pow(gamma, Gamma);
float Fp = Lpm * Jp * exp(-Omega / sqrt(10.0) * (sqrt(k / kp) - 1.0));
float alphap = 0.006 * sqrt(Omega);
float Bl = 0.5 * alphap * cp / c * Fp;
float z0 = 0.000037 * pow2(l_wind) / G * pow(l_wind / cp, 0.9);
float uStar = 0.41 * l_wind / log(10.0 / z0);
float alpham = 0.01 * ((uStar < CM) ? (1.0 + log(uStar / CM)) : (1.0 + 3.0 * log(uStar / CM)));
float Fm = exp(-0.25 * pow2(k / KM - 1.0));
float Bh = 0.5 * alpham * CM / c * Fm * Lpm;
float a0 = log(2.0) / 4.0;
float am = 0.13 * uStar / CM;
float Delta = tanh(a0 + 4.0 * pow(c / cp, 2.5) + am * pow(CM / c, 2.5));
float cosPhi = dot(normalize(u_wind), normalize(K));
float S = (1.0 / (2.0 * PI)) * pow(k, -4.0) * (Bl + Bh) * (1.0 + Delta * (2.0 * cosPhi * cosPhi - 1.0));
float dk = 2.0 * PI / u_size;
float h = sqrt(S / 2.0) * dk;
if (K.x == 0.0 && K.y == 0.0) {
h = 0.0; //no DC term
}
gl_FragColor = vec4(h, 0.0, 0.0, 0.0);
}
`
}
};
OceanShaderLib['ocean_phase'] = function() {
return {
uniforms: {
u_phases: { value: null },
u_deltaTime: { value: null },
u_resolution: { value: null },
u_size: { value: null }
},
fragmentShader: `
precision highp float;
const float G = 9.81;
const float KM = 370.0;
varying vec2 vUV;
uniform sampler2D u_phases;
uniform float u_deltaTime;
uniform float u_resolution;
uniform float u_size;
float omega (float k) {
return sqrt(G * k * (1.0 + k * k / KM * KM));
}
void main (void) {
float deltaTime = 1.0 / 60.0;
vec2 coordinates = gl_FragCoord.xy - 0.5;
float n = (coordinates.x < u_resolution * 0.5) ? coordinates.x : coordinates.x - u_resolution;
float m = (coordinates.y < u_resolution * 0.5) ? coordinates.y : coordinates.y - u_resolution;
vec2 waveVector = (2.0 * PI * vec2(n, m)) / u_size;
float phase = texture2D(u_phases, vUV).r;
float deltaPhase = omega(length(waveVector)) * u_deltaTime;
phase = mod(phase + deltaPhase, 2.0 * PI);
gl_FragColor = vec4(phase, 0.0, 0.0, 0.0);
}
`
}
};
OceanShaderLib['ocean_spectrum'] = function() {
return {
uniforms: {
u_size: { value: null },
u_resolution: { value: null },
u_choppiness: { value: null },
u_phases: { value: null },
u_initialSpectrum: { value: null }
},
fragmentShader: `
precision highp float;
const float G = 9.81;
const float KM = 370.0;
varying vec2 vUV;
uniform float u_size;
uniform float u_resolution;
uniform float u_choppiness;
uniform sampler2D u_phases;
uniform sampler2D u_initialSpectrum;
vec2 multiplyComplex (vec2 a, vec2 b) {
return vec2(a[0] * b[0] - a[1] * b[1], a[1] * b[0] + a[0] * b[1]);
}
vec2 multiplyByI (vec2 z) {
return vec2(-z[1], z[0]);
}
float omega (float k) {
return sqrt(G * k * (1.0 + k * k / KM * KM));
}
void main (void) {
vec2 coordinates = gl_FragCoord.xy - 0.5;
float n = (coordinates.x < u_resolution * 0.5) ? coordinates.x : coordinates.x - u_resolution;
float m = (coordinates.y < u_resolution * 0.5) ? coordinates.y : coordinates.y - u_resolution;
vec2 waveVector = (2.0 * PI * vec2(n, m)) / u_size;
float phase = texture2D(u_phases, vUV).r;
vec2 phaseVector = vec2(cos(phase), sin(phase));
vec2 h0 = texture2D(u_initialSpectrum, vUV).rg;
vec2 h0Star = texture2D(u_initialSpectrum, vec2(1.0 - vUV + 1.0 / u_resolution)).rg;
h0Star.y *= -1.0;
vec2 h = multiplyComplex(h0, phaseVector) + multiplyComplex(h0Star, vec2(phaseVector.x, -phaseVector.y));
vec2 hX = -multiplyByI(h * (waveVector.x / length(waveVector))) * u_choppiness;
vec2 hZ = -multiplyByI(h * (waveVector.y / length(waveVector))) * u_choppiness;
//no DC term
if (waveVector.x == 0.0 && waveVector.y == 0.0) {
h = vec2(0.0);
hX = vec2(0.0);
hZ = vec2(0.0);
}
gl_FragColor = vec4(hX + multiplyByI(h), hZ);
}
`
}
};
OceanShaderLib['ocean_normals'] = function() {
return {
uniforms: {
u_displacementMap: { value: null },
u_resolution: { value: null },
u_size: { value: null }
},
fragmentShader: `
precision highp float;
varying vec2 vUV;
uniform sampler2D u_displacementMap;
uniform float u_resolution;
uniform float u_size;
void main (void) {
float texel = 1.0 / u_resolution;
float texelSize = u_size / u_resolution;
vec3 center = texture2D(u_displacementMap, vUV).rgb;
vec3 right = vec3(texelSize, 0.0, 0.0) + texture2D(u_displacementMap, vUV + vec2(texel, 0.0)).rgb - center;
vec3 left = vec3(-texelSize, 0.0, 0.0) + texture2D(u_displacementMap, vUV + vec2(-texel, 0.0)).rgb - center;
vec3 top = vec3(0.0, 0.0, -texelSize) + texture2D(u_displacementMap, vUV + vec2(0.0, -texel)).rgb - center;
vec3 bottom = vec3(0.0, 0.0, texelSize) + texture2D(u_displacementMap, vUV + vec2(0.0, texel)).rgb - center;
vec3 topRight = cross(right, top);
vec3 topLeft = cross(top, left);
vec3 bottomLeft = cross(left, bottom);
vec3 bottomRight = cross(bottom, right);
gl_FragColor = vec4(normalize(topRight + topLeft + bottomLeft + bottomRight), 1.0);
}
`
}
};
OceanShaderLib['ocean_main'] = function() {
return {
uniforms: {
u_displacementMap: { value: null },
u_normalMap: { value: null },
u_geometrySize: { value: null },
u_size: { value: null },
u_projectionMatrix: { value: null },
u_viewMatrix: { value: null },
u_cameraPosition: { value: null },
u_skyColor: { value: null },
u_oceanColor: { value: null },
u_sunDirection: { value: null },
u_exposure: { value: null }
},
vertexShader: `
precision highp float;
varying vec3 vPos;
varying vec2 vUV;
uniform mat4 u_projectionMatrix;
uniform mat4 u_viewMatrix;
uniform float u_size;
uniform float u_geometrySize;
uniform sampler2D u_displacementMap;
void main (void) {
vec3 newPos = position + texture2D(u_displacementMap, uv).rgb * (u_geometrySize / u_size);
vPos = newPos;
vUV = uv;
gl_Position = u_projectionMatrix * u_viewMatrix * vec4(newPos, 1.0);
}
`,
fragmentShader: `
precision highp float;
varying vec3 vPos;
varying vec2 vUV;
uniform sampler2D u_displacementMap;
uniform sampler2D u_normalMap;
uniform vec3 u_cameraPosition;
uniform vec3 u_oceanColor;
uniform vec3 u_skyColor;
uniform vec3 u_sunDirection;
uniform float u_exposure;
vec3 hdr (vec3 color, float exposure) {
return 1.0 - exp(-color * exposure);
}
void main (void) {
vec3 normal = texture2D(u_normalMap, vUV).rgb;
vec3 view = normalize(u_cameraPosition - vPos);
float fresnel = 0.02 + 0.98 * pow(1.0 - dot(normal, view), 5.0);
vec3 sky = fresnel * u_skyColor;
float diffuse = clamp(dot(normal, normalize(u_sunDirection)), 0.0, 1.0);
vec3 water = (1.0 - fresnel) * u_oceanColor * u_skyColor * diffuse;
vec3 color = sky + water;
gl_FragColor = vec4(hdr(color, u_exposure), 1.0);
}
`
}
};
module.exports = OceanShaderLib;