import {
Color,
Mesh,
Vector3,
MeshLambertNodeMaterial
} from 'three/webgpu';
import { Fn, add, cameraPosition, div, normalize, positionWorld, sub, time, texture, vec2, vec3, max, dot, reflect, pow, length, float, uniform, reflector, mul, mix, diffuseColor } from 'three/tsl';
/**
* Work based on :
* https://github.com/Slayvin: Flat mirror for three.js
* https://home.adelphi.edu/~stemkoski/ : An implementation of water shader based on the flat mirror
* http://29a.ch/ && http://29a.ch/slides/2012/webglwater/ : Water shader explanations in WebGL
*/
class WaterMesh extends Mesh {
constructor( geometry, options ) {
const material = new MeshLambertNodeMaterial();
super( geometry, material );
this.isWater = true;
this.resolution = options.resolution !== undefined ? options.resolution : 0.5;
// Uniforms
this.waterNormals = texture( options.waterNormals );
this.alpha = uniform( options.alpha !== undefined ? options.alpha : 1.0 );
this.size = uniform( options.size !== undefined ? options.size : 1.0 );
this.sunColor = uniform( new Color( options.sunColor !== undefined ? options.sunColor : 0xffffff ) );
this.sunDirection = uniform( options.sunDirection !== undefined ? options.sunDirection : new Vector3( 0.70707, 0.70707, 0.0 ) );
this.waterColor = uniform( new Color( options.waterColor !== undefined ? options.waterColor : 0x7f7f7f ) );
this.distortionScale = uniform( options.distortionScale !== undefined ? options.distortionScale : 20.0 );
// TSL
const getNoise = Fn( ( [ uv ] ) => {
const offset = time;
const uv0 = add( div( uv, 103 ), vec2( div( offset, 17 ), div( offset, 29 ) ) ).toVar();
const uv1 = div( uv, 107 ).sub( vec2( div( offset, - 19 ), div( offset, 31 ) ) ).toVar();
const uv2 = add( div( uv, vec2( 8907.0, 9803.0 ) ), vec2( div( offset, 101 ), div( offset, 97 ) ) ).toVar();
const uv3 = sub( div( uv, vec2( 1091.0, 1027.0 ) ), vec2( div( offset, 109 ), div( offset, - 113 ) ) ).toVar();
const sample0 = this.waterNormals.sample( uv0 );
const sample1 = this.waterNormals.sample( uv1 );
const sample2 = this.waterNormals.sample( uv2 );
const sample3 = this.waterNormals.sample( uv3 );
const noise = sample0.add( sample1 ).add( sample2 ).add( sample3 );
return noise.mul( 0.5 ).sub( 1 );
} );
const noise = getNoise( positionWorld.xz.mul( this.size ) );
const surfaceNormal = normalize( noise.xzy.mul( 1.5, 1.0, 1.5 ) );
const worldToEye = cameraPosition.sub( positionWorld );
const eyeDirection = normalize( worldToEye );
const reflection = normalize( reflect( this.sunDirection.negate(), surfaceNormal ) );
const direction = max( 0.0, dot( eyeDirection, reflection ) );
const specularLight = pow( direction, 100 ).mul( this.sunColor ).mul( 2.0 );
const diffuseLight = max( dot( this.sunDirection, surfaceNormal ), 0.0 ).mul( this.sunColor ).mul( 0.5 );
const distance = length( worldToEye );
const distortion = surfaceNormal.xz.mul( float( 0.001 ).add( float( 1.0 ).div( distance ) ) ).mul( this.distortionScale );
// Material
material.transparent = true;
material.opacityNode = this.alpha;
material.shadowPositionNode = positionWorld.add( distortion );
material.setupOutgoingLight = () => diffuseColor.rgb; // backwards compatibility
material.colorNode = Fn( () => {
const mirrorSampler = reflector();
mirrorSampler.uvNode = mirrorSampler.uvNode.add( distortion );
mirrorSampler.resolution = this.resolution;
this.add( mirrorSampler.target );
const theta = max( dot( eyeDirection, surfaceNormal ), 0.0 );
const rf0 = float( 0.3 );
const reflectance = mul( pow( float( 1.0 ).sub( theta ), 5.0 ), float( 1.0 ).sub( rf0 ) ).add( rf0 );
const scatter = max( 0.0, dot( surfaceNormal, eyeDirection ) ).mul( this.waterColor );
const albedo = mix( this.sunColor.mul( diffuseLight ).mul( 0.3 ).add( scatter ), mirrorSampler.rgb.mul( specularLight ).add( mirrorSampler.rgb.mul( 0.9 ) ).add( vec3( 0.1 ) ), reflectance );
return albedo;
} )();
}
}
export { WaterMesh };