Accueil / npm / three@0.152.1 / examples / jsm / geometries / LightningStrike.js
LightningStrike.js
import {
BufferGeometry,
DynamicDrawUsage,
Float32BufferAttribute,
MathUtils,
Uint32BufferAttribute,
Vector3
} from 'three';
import { SimplexNoise } from '../math/SimplexNoise.js';
/**
* @fileoverview LightningStrike object for creating lightning strikes and voltaic arcs.
*
*
* Usage
*
* var myRay = new LightningStrike( paramsObject );
* var myRayMesh = new THREE.Mesh( myRay, myMaterial );
* scene.add( myRayMesh );
* ...
* myRay.update( currentTime );
*
* The "currentTime" can vary its rate, go forwards, backwards or even jump, but it cannot be negative.
*
* You should normally leave the ray position to (0, 0, 0). You should control it by changing the sourceOffset and destOffset parameters.
*
*
* LightningStrike parameters
*
* The paramsObject can contain any of the following parameters.
*
* Legend:
* 'LightningStrike' (also called 'ray'): An independent voltaic arc with its ramifications and defined with a set of parameters.
* 'Subray': A ramification of the ray. It is not a LightningStrike object.
* 'Segment': A linear segment piece of a subray.
* 'Leaf segment': A ray segment which cannot be smaller.
*
*
* The following parameters can be changed any time and if they vary smoothly, the ray form will also change smoothly:
*
* @param {Vector3} sourceOffset The point where the ray starts.
*
* @param {Vector3} destOffset The point where the ray ends.
*
* @param {double} timeScale The rate at wich the ray form changes in time. Default: 1
*
* @param {double} roughness From 0 to 1. The higher the value, the more wrinkled is the ray. Default: 0.9
*
* @param {double} straightness From 0 to 1. The higher the value, the more straight will be a subray path. Default: 0.7
*
* @param {Vector3} up0 Ray 'up' direction at the ray starting point. Must be normalized. It should be perpendicular to the ray forward direction but it doesn't matter much.
*
* @param {Vector3} up1 Like the up0 parameter but at the end of the ray. Must be normalized.
*
* @param {double} radius0 Radius of the main ray trunk at the start point. Default: 1
*
* @param {double} radius1 Radius of the main ray trunk at the end point. Default: 1
*
* @param {double} radius0Factor The radius0 of a subray is this factor times the radius0 of its parent subray. Default: 0.5
*
* @param {double} radius1Factor The radius1 of a subray is this factor times the radius1 of its parent subray. Default: 0.2
*
* @param {minRadius} Minimum value a subray radius0 or radius1 can get. Default: 0.1
*
*
* The following parameters should not be changed after lightning creation. They can be changed but the ray will change its form abruptly:
*
* @param {boolean} isEternal If true the ray never extinguishes. Otherwise its life is controlled by the 'birthTime' and 'deathTime' parameters. Default: true if any of those two parameters is undefined.
*
* @param {double} birthTime The time at which the ray starts its life and begins propagating. Only if isEternal is false. Default: None.
*
* @param {double} deathTime The time at which the ray ends vanishing and its life. Only if isEternal is false. Default: None.
*
* @param {double} propagationTimeFactor From 0 to 1. Lifetime factor at which the ray ends propagating and enters the steady phase. For example, 0.1 means it is propagating 1/10 of its lifetime. Default: 0.1
*
* @param {double} vanishingTimeFactor From 0 to 1. Lifetime factor at which the ray ends the steady phase and begins vanishing. For example, 0.9 means it is vanishing 1/10 of its lifetime. Default: 0.9
*
* @param {double} subrayPeriod Subrays cycle periodically. This is their time period. Default: 4
*
* @param {double} subrayDutyCycle From 0 to 1. This is the fraction of time a subray is active. Default: 0.6
*
*
* These parameters cannot change after lightning creation:
*
* @param {integer} maxIterations: Greater than 0. The number of ray's leaf segments is 2**maxIterations. Default: 9
*
* @param {boolean} isStatic Set to true only for rays which won't change over time and are not attached to moving objects (Rare case). It is used to set the vertex buffers non-dynamic. You can omit calling update() for these rays.
*
* @param {integer} ramification Greater than 0. Maximum number of child subrays a subray can have. Default: 5
*
* @param {integer} maxSubrayRecursion Greater than 0. Maximum level of recursion (subray descendant generations). Default: 3
*
* @param {double} recursionProbability From 0 to 1. The lower the value, the less chance each new generation of subrays has to generate new subrays. Default: 0.6
*
* @param {boolean} generateUVs If true, the ray geometry will have uv coordinates generated. u runs along the ray, and v across its perimeter. Default: false.
*
* @param {Object} randomGenerator Set here your random number generator which will seed the SimplexNoise and other decisions during ray tree creation.
* It can be used to generate repeatable rays. For that, set also the noiseSeed parameter, and each ray created with that generator and seed pair will be identical in time.
* The randomGenerator parameter should be an object with a random() function similar to Math.random, but seedable.
* It must have also a getSeed() method, which returns the current seed, and a setSeed( seed ) method, which accepts as seed a fractional number from 0 to 1, as well as any other number.
* The default value is an internal generator for some uses and Math.random for others (It is non-repeatable even if noiseSeed is supplied)
*
* @param {double} noiseSeed Seed used to make repeatable rays (see the randomGenerator)
*
* @param {function} onDecideSubrayCreation Set this to change the callback which decides subray creation. You can look at the default callback in the code (createDefaultSubrayCreationCallbacks)for more info.
*
* @param {function} onSubrayCreation This is another callback, more simple than the previous one. It can be used to adapt the form of subrays or other parameters once a subray has been created and initialized. It is used in the examples to adapt subrays to a sphere or to a plane.
*
*
*/
class LightningStrike extends BufferGeometry {
constructor( rayParameters = {} ) {
super();
this.isLightningStrike = true;
this.type = 'LightningStrike';
// Set parameters, and set undefined parameters to default values
this.init( LightningStrike.copyParameters( rayParameters, rayParameters ) );
// Creates and populates the mesh
this.createMesh();
}
static createRandomGenerator() {
const numSeeds = 2053;
const seeds = [];
for ( let i = 0; i < numSeeds; i ++ ) {
seeds.push( Math.random() );
}
const generator = {
currentSeed: 0,
random: function () {
const value = seeds[ generator.currentSeed ];
generator.currentSeed = ( generator.currentSeed + 1 ) % numSeeds;
return value;
},
getSeed: function () {
return generator.currentSeed / numSeeds;
},
setSeed: function ( seed ) {
generator.currentSeed = Math.floor( seed * numSeeds ) % numSeeds;
}
};
return generator;
}
static copyParameters( dest = {}, source = {} ) {
const vecCopy = function ( v ) {
if ( source === dest ) {
return v;
} else {
return v.clone();
}
};
dest.sourceOffset = source.sourceOffset !== undefined ? vecCopy( source.sourceOffset ) : new Vector3( 0, 100, 0 ),
dest.destOffset = source.destOffset !== undefined ? vecCopy( source.destOffset ) : new Vector3( 0, 0, 0 ),
dest.timeScale = source.timeScale !== undefined ? source.timeScale : 1,
dest.roughness = source.roughness !== undefined ? source.roughness : 0.9,
dest.straightness = source.straightness !== undefined ? source.straightness : 0.7,
dest.up0 = source.up0 !== undefined ? vecCopy( source.up0 ) : new Vector3( 0, 0, 1 );
dest.up1 = source.up1 !== undefined ? vecCopy( source.up1 ) : new Vector3( 0, 0, 1 ),
dest.radius0 = source.radius0 !== undefined ? source.radius0 : 1,
dest.radius1 = source.radius1 !== undefined ? source.radius1 : 1,
dest.radius0Factor = source.radius0Factor !== undefined ? source.radius0Factor : 0.5,
dest.radius1Factor = source.radius1Factor !== undefined ? source.radius1Factor : 0.2,
dest.minRadius = source.minRadius !== undefined ? source.minRadius : 0.2,
// These parameters should not be changed after lightning creation. They can be changed but the ray will change its form abruptly:
dest.isEternal = source.isEternal !== undefined ? source.isEternal : ( source.birthTime === undefined || source.deathTime === undefined ),
dest.birthTime = source.birthTime,
dest.deathTime = source.deathTime,
dest.propagationTimeFactor = source.propagationTimeFactor !== undefined ? source.propagationTimeFactor : 0.1,
dest.vanishingTimeFactor = source.vanishingTimeFactor !== undefined ? source.vanishingTimeFactor : 0.9,
dest.subrayPeriod = source.subrayPeriod !== undefined ? source.subrayPeriod : 4,
dest.subrayDutyCycle = source.subrayDutyCycle !== undefined ? source.subrayDutyCycle : 0.6;
// These parameters cannot change after lightning creation:
dest.maxIterations = source.maxIterations !== undefined ? source.maxIterations : 9;
dest.isStatic = source.isStatic !== undefined ? source.isStatic : false;
dest.ramification = source.ramification !== undefined ? source.ramification : 5;
dest.maxSubrayRecursion = source.maxSubrayRecursion !== undefined ? source.maxSubrayRecursion : 3;
dest.recursionProbability = source.recursionProbability !== undefined ? source.recursionProbability : 0.6;
dest.generateUVs = source.generateUVs !== undefined ? source.generateUVs : false;
dest.randomGenerator = source.randomGenerator,
dest.noiseSeed = source.noiseSeed,
dest.onDecideSubrayCreation = source.onDecideSubrayCreation,
dest.onSubrayCreation = source.onSubrayCreation;
return dest;
}
update( time ) {
if ( this.isStatic ) return;
if ( this.rayParameters.isEternal || ( this.rayParameters.birthTime <= time && time <= this.rayParameters.deathTime ) ) {
this.updateMesh( time );
if ( time < this.subrays[ 0 ].endPropagationTime ) {
this.state = LightningStrike.RAY_PROPAGATING;
} else if ( time > this.subrays[ 0 ].beginVanishingTime ) {
this.state = LightningStrike.RAY_VANISHING;
} else {
this.state = LightningStrike.RAY_STEADY;
}
this.visible = true;
} else {
this.visible = false;
if ( time < this.rayParameters.birthTime ) {
this.state = LightningStrike.RAY_UNBORN;
} else {
this.state = LightningStrike.RAY_EXTINGUISHED;
}
}
}
init( rayParameters ) {
// Init all the state from the parameters
this.rayParameters = rayParameters;
// These parameters cannot change after lightning creation:
this.maxIterations = rayParameters.maxIterations !== undefined ? Math.floor( rayParameters.maxIterations ) : 9;
rayParameters.maxIterations = this.maxIterations;
this.isStatic = rayParameters.isStatic !== undefined ? rayParameters.isStatic : false;
rayParameters.isStatic = this.isStatic;
this.ramification = rayParameters.ramification !== undefined ? Math.floor( rayParameters.ramification ) : 5;
rayParameters.ramification = this.ramification;
this.maxSubrayRecursion = rayParameters.maxSubrayRecursion !== undefined ? Math.floor( rayParameters.maxSubrayRecursion ) : 3;
rayParameters.maxSubrayRecursion = this.maxSubrayRecursion;
this.recursionProbability = rayParameters.recursionProbability !== undefined ? rayParameters.recursionProbability : 0.6;
rayParameters.recursionProbability = this.recursionProbability;
this.generateUVs = rayParameters.generateUVs !== undefined ? rayParameters.generateUVs : false;
rayParameters.generateUVs = this.generateUVs;
// Random generator
if ( rayParameters.randomGenerator !== undefined ) {
this.randomGenerator = rayParameters.randomGenerator;
this.seedGenerator = rayParameters.randomGenerator;
if ( rayParameters.noiseSeed !== undefined ) {
this.seedGenerator.setSeed( rayParameters.noiseSeed );
}
} else {
this.randomGenerator = LightningStrike.createRandomGenerator();
this.seedGenerator = Math;
}
// Ray creation callbacks
if ( rayParameters.onDecideSubrayCreation !== undefined ) {
this.onDecideSubrayCreation = rayParameters.onDecideSubrayCreation;
} else {
this.createDefaultSubrayCreationCallbacks();
if ( rayParameters.onSubrayCreation !== undefined ) {
this.onSubrayCreation = rayParameters.onSubrayCreation;
}
}
// Internal state
this.state = LightningStrike.RAY_INITIALIZED;
this.maxSubrays = Math.ceil( 1 + Math.pow( this.ramification, Math.max( 0, this.maxSubrayRecursion - 1 ) ) );
rayParameters.maxSubrays = this.maxSubrays;
this.maxRaySegments = 2 * ( 1 << this.maxIterations );
this.subrays = [];
for ( let i = 0; i < this.maxSubrays; i ++ ) {
this.subrays.push( this.createSubray() );
}
this.raySegments = [];
for ( let i = 0; i < this.maxRaySegments; i ++ ) {
this.raySegments.push( this.createSegment() );
}
this.time = 0;
this.timeFraction = 0;
this.currentSegmentCallback = null;
this.currentCreateTriangleVertices = this.generateUVs ? this.createTriangleVerticesWithUVs : this.createTriangleVerticesWithoutUVs;
this.numSubrays = 0;
this.currentSubray = null;
this.currentSegmentIndex = 0;
this.isInitialSegment = false;
this.subrayProbability = 0;
this.currentVertex = 0;
this.currentIndex = 0;
this.currentCoordinate = 0;
this.currentUVCoordinate = 0;
this.vertices = null;
this.uvs = null;
this.indices = null;
this.positionAttribute = null;
this.uvsAttribute = null;
this.simplexX = new SimplexNoise( this.seedGenerator );
this.simplexY = new SimplexNoise( this.seedGenerator );
this.simplexZ = new SimplexNoise( this.seedGenerator );
// Temp vectors
this.forwards = new Vector3();
this.forwardsFill = new Vector3();
this.side = new Vector3();
this.down = new Vector3();
this.middlePos = new Vector3();
this.middleLinPos = new Vector3();
this.newPos = new Vector3();
this.vPos = new Vector3();
this.cross1 = new Vector3();
}
createMesh() {
const maxDrawableSegmentsPerSubRay = 1 << this.maxIterations;
const maxVerts = 3 * ( maxDrawableSegmentsPerSubRay + 1 ) * this.maxSubrays;
const maxIndices = 18 * maxDrawableSegmentsPerSubRay * this.maxSubrays;
this.vertices = new Float32Array( maxVerts * 3 );
this.indices = new Uint32Array( maxIndices );
if ( this.generateUVs ) {
this.uvs = new Float32Array( maxVerts * 2 );
}
// Populate the mesh
this.fillMesh( 0 );
this.setIndex( new Uint32BufferAttribute( this.indices, 1 ) );
this.positionAttribute = new Float32BufferAttribute( this.vertices, 3 );
this.setAttribute( 'position', this.positionAttribute );
if ( this.generateUVs ) {
this.uvsAttribute = new Float32BufferAttribute( new Float32Array( this.uvs ), 2 );
this.setAttribute( 'uv', this.uvsAttribute );
}
if ( ! this.isStatic ) {
this.index.usage = DynamicDrawUsage;
this.positionAttribute.usage = DynamicDrawUsage;
if ( this.generateUVs ) {
this.uvsAttribute.usage = DynamicDrawUsage;
}
}
// Store buffers for later modification
this.vertices = this.positionAttribute.array;
this.indices = this.index.array;
if ( this.generateUVs ) {
this.uvs = this.uvsAttribute.array;
}
}
updateMesh( time ) {
this.fillMesh( time );
this.drawRange.count = this.currentIndex;
this.index.needsUpdate = true;
this.positionAttribute.needsUpdate = true;
if ( this.generateUVs ) {
this.uvsAttribute.needsUpdate = true;
}
}
fillMesh( time ) {
const scope = this;
this.currentVertex = 0;
this.currentIndex = 0;
this.currentCoordinate = 0;
this.currentUVCoordinate = 0;
this.fractalRay( time, function fillVertices( segment ) {
const subray = scope.currentSubray;
if ( time < subray.birthTime ) { //&& ( ! this.rayParameters.isEternal || scope.currentSubray.recursion > 0 ) ) {
return;
} else if ( this.rayParameters.isEternal && scope.currentSubray.recursion == 0 ) {
// Eternal rays don't propagate nor vanish, but its subrays do
scope.createPrism( segment );
scope.onDecideSubrayCreation( segment, scope );
} else if ( time < subray.endPropagationTime ) {
if ( scope.timeFraction >= segment.fraction0 * subray.propagationTimeFactor ) {
// Ray propagation has arrived to this segment
scope.createPrism( segment );
scope.onDecideSubrayCreation( segment, scope );
}
} else if ( time < subray.beginVanishingTime ) {
// Ray is steady (nor propagating nor vanishing)
scope.createPrism( segment );
scope.onDecideSubrayCreation( segment, scope );
} else {
if ( scope.timeFraction <= subray.vanishingTimeFactor + segment.fraction1 * ( 1 - subray.vanishingTimeFactor ) ) {
// Segment has not yet vanished
scope.createPrism( segment );
}
scope.onDecideSubrayCreation( segment, scope );
}
} );
}
addNewSubray( /*rayParameters*/ ) {
return this.subrays[ this.numSubrays ++ ];
}
initSubray( subray, rayParameters ) {
subray.pos0.copy( rayParameters.sourceOffset );
subray.pos1.copy( rayParameters.destOffset );
subray.up0.copy( rayParameters.up0 );
subray.up1.copy( rayParameters.up1 );
subray.radius0 = rayParameters.radius0;
subray.radius1 = rayParameters.radius1;
subray.birthTime = rayParameters.birthTime;
subray.deathTime = rayParameters.deathTime;
subray.timeScale = rayParameters.timeScale;
subray.roughness = rayParameters.roughness;
subray.straightness = rayParameters.straightness;
subray.propagationTimeFactor = rayParameters.propagationTimeFactor;
subray.vanishingTimeFactor = rayParameters.vanishingTimeFactor;
subray.maxIterations = this.maxIterations;
subray.seed = rayParameters.noiseSeed !== undefined ? rayParameters.noiseSeed : 0;
subray.recursion = 0;
}
fractalRay( time, segmentCallback ) {
this.time = time;
this.currentSegmentCallback = segmentCallback;
this.numSubrays = 0;
// Add the top level subray
this.initSubray( this.addNewSubray(), this.rayParameters );
// Process all subrays that are being generated until consuming all of them
for ( let subrayIndex = 0; subrayIndex < this.numSubrays; subrayIndex ++ ) {
const subray = this.subrays[ subrayIndex ];
this.currentSubray = subray;
this.randomGenerator.setSeed( subray.seed );
subray.endPropagationTime = MathUtils.lerp( subray.birthTime, subray.deathTime, subray.propagationTimeFactor );
subray.beginVanishingTime = MathUtils.lerp( subray.deathTime, subray.birthTime, 1 - subray.vanishingTimeFactor );
const random1 = this.randomGenerator.random;
subray.linPos0.set( random1(), random1(), random1() ).multiplyScalar( 1000 );
subray.linPos1.set( random1(), random1(), random1() ).multiplyScalar( 1000 );
this.timeFraction = ( time - subray.birthTime ) / ( subray.deathTime - subray.birthTime );
this.currentSegmentIndex = 0;
this.isInitialSegment = true;
const segment = this.getNewSegment();
segment.iteration = 0;
segment.pos0.copy( subray.pos0 );
segment.pos1.copy( subray.pos1 );
segment.linPos0.copy( subray.linPos0 );
segment.linPos1.copy( subray.linPos1 );
segment.up0.copy( subray.up0 );
segment.up1.copy( subray.up1 );
segment.radius0 = subray.radius0;
segment.radius1 = subray.radius1;
segment.fraction0 = 0;
segment.fraction1 = 1;
segment.positionVariationFactor = 1 - subray.straightness;
this.subrayProbability = this.ramification * Math.pow( this.recursionProbability, subray.recursion ) / ( 1 << subray.maxIterations );
this.fractalRayRecursive( segment );
}
this.currentSegmentCallback = null;
this.currentSubray = null;
}
fractalRayRecursive( segment ) {
// Leave recursion condition
if ( segment.iteration >= this.currentSubray.maxIterations ) {
this.currentSegmentCallback( segment );
return;
}
// Interpolation
this.forwards.subVectors( segment.pos1, segment.pos0 );
let lForwards = this.forwards.length();
if ( lForwards < 0.000001 ) {
this.forwards.set( 0, 0, 0.01 );
lForwards = this.forwards.length();
}
const middleRadius = ( segment.radius0 + segment.radius1 ) * 0.5;
const middleFraction = ( segment.fraction0 + segment.fraction1 ) * 0.5;
const timeDimension = this.time * this.currentSubray.timeScale * Math.pow( 2, segment.iteration );
this.middlePos.lerpVectors( segment.pos0, segment.pos1, 0.5 );
this.middleLinPos.lerpVectors( segment.linPos0, segment.linPos1, 0.5 );
const p = this.middleLinPos;
// Noise
this.newPos.set( this.simplexX.noise4d( p.x, p.y, p.z, timeDimension ),
this.simplexY.noise4d( p.x, p.y, p.z, timeDimension ),
this.simplexZ.noise4d( p.x, p.y, p.z, timeDimension ) );
this.newPos.multiplyScalar( segment.positionVariationFactor * lForwards );
this.newPos.add( this.middlePos );
// Recursion
const newSegment1 = this.getNewSegment();
newSegment1.pos0.copy( segment.pos0 );
newSegment1.pos1.copy( this.newPos );
newSegment1.linPos0.copy( segment.linPos0 );
newSegment1.linPos1.copy( this.middleLinPos );
newSegment1.up0.copy( segment.up0 );
newSegment1.up1.copy( segment.up1 );
newSegment1.radius0 = segment.radius0;
newSegment1.radius1 = middleRadius;
newSegment1.fraction0 = segment.fraction0;
newSegment1.fraction1 = middleFraction;
newSegment1.positionVariationFactor = segment.positionVariationFactor * this.currentSubray.roughness;
newSegment1.iteration = segment.iteration + 1;
const newSegment2 = this.getNewSegment();
newSegment2.pos0.copy( this.newPos );
newSegment2.pos1.copy( segment.pos1 );
newSegment2.linPos0.copy( this.middleLinPos );
newSegment2.linPos1.copy( segment.linPos1 );
this.cross1.crossVectors( segment.up0, this.forwards.normalize() );
newSegment2.up0.crossVectors( this.forwards, this.cross1 ).normalize();
newSegment2.up1.copy( segment.up1 );
newSegment2.radius0 = middleRadius;
newSegment2.radius1 = segment.radius1;
newSegment2.fraction0 = middleFraction;
newSegment2.fraction1 = segment.fraction1;
newSegment2.positionVariationFactor = segment.positionVariationFactor * this.currentSubray.roughness;
newSegment2.iteration = segment.iteration + 1;
this.fractalRayRecursive( newSegment1 );
this.fractalRayRecursive( newSegment2 );
}
createPrism( segment ) {
// Creates one triangular prism and its vertices at the segment
this.forwardsFill.subVectors( segment.pos1, segment.pos0 ).normalize();
if ( this.isInitialSegment ) {
this.currentCreateTriangleVertices( segment.pos0, segment.up0, this.forwardsFill, segment.radius0, 0 );
this.isInitialSegment = false;
}
this.currentCreateTriangleVertices( segment.pos1, segment.up0, this.forwardsFill, segment.radius1, segment.fraction1 );
this.createPrismFaces();
}
createTriangleVerticesWithoutUVs( pos, up, forwards, radius ) {
// Create an equilateral triangle (only vertices)
this.side.crossVectors( up, forwards ).multiplyScalar( radius * LightningStrike.COS30DEG );
this.down.copy( up ).multiplyScalar( - radius * LightningStrike.SIN30DEG );
const p = this.vPos;
const v = this.vertices;
p.copy( pos ).sub( this.side ).add( this.down );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
p.copy( pos ).add( this.side ).add( this.down );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
p.copy( up ).multiplyScalar( radius ).add( pos );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
this.currentVertex += 3;
}
createTriangleVerticesWithUVs( pos, up, forwards, radius, u ) {
// Create an equilateral triangle (only vertices)
this.side.crossVectors( up, forwards ).multiplyScalar( radius * LightningStrike.COS30DEG );
this.down.copy( up ).multiplyScalar( - radius * LightningStrike.SIN30DEG );
const p = this.vPos;
const v = this.vertices;
const uv = this.uvs;
p.copy( pos ).sub( this.side ).add( this.down );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
uv[ this.currentUVCoordinate ++ ] = u;
uv[ this.currentUVCoordinate ++ ] = 0;
p.copy( pos ).add( this.side ).add( this.down );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
uv[ this.currentUVCoordinate ++ ] = u;
uv[ this.currentUVCoordinate ++ ] = 0.5;
p.copy( up ).multiplyScalar( radius ).add( pos );
v[ this.currentCoordinate ++ ] = p.x;
v[ this.currentCoordinate ++ ] = p.y;
v[ this.currentCoordinate ++ ] = p.z;
uv[ this.currentUVCoordinate ++ ] = u;
uv[ this.currentUVCoordinate ++ ] = 1;
this.currentVertex += 3;
}
createPrismFaces( vertex/*, index*/ ) {
const indices = this.indices;
vertex = this.currentVertex - 6;
indices[ this.currentIndex ++ ] = vertex + 1;
indices[ this.currentIndex ++ ] = vertex + 2;
indices[ this.currentIndex ++ ] = vertex + 5;
indices[ this.currentIndex ++ ] = vertex + 1;
indices[ this.currentIndex ++ ] = vertex + 5;
indices[ this.currentIndex ++ ] = vertex + 4;
indices[ this.currentIndex ++ ] = vertex + 0;
indices[ this.currentIndex ++ ] = vertex + 1;
indices[ this.currentIndex ++ ] = vertex + 4;
indices[ this.currentIndex ++ ] = vertex + 0;
indices[ this.currentIndex ++ ] = vertex + 4;
indices[ this.currentIndex ++ ] = vertex + 3;
indices[ this.currentIndex ++ ] = vertex + 2;
indices[ this.currentIndex ++ ] = vertex + 0;
indices[ this.currentIndex ++ ] = vertex + 3;
indices[ this.currentIndex ++ ] = vertex + 2;
indices[ this.currentIndex ++ ] = vertex + 3;
indices[ this.currentIndex ++ ] = vertex + 5;
}
createDefaultSubrayCreationCallbacks() {
const random1 = this.randomGenerator.random;
this.onDecideSubrayCreation = function ( segment, lightningStrike ) {
// Decide subrays creation at parent (sub)ray segment
const subray = lightningStrike.currentSubray;
const period = lightningStrike.rayParameters.subrayPeriod;
const dutyCycle = lightningStrike.rayParameters.subrayDutyCycle;
const phase0 = ( lightningStrike.rayParameters.isEternal && subray.recursion == 0 ) ? - random1() * period : MathUtils.lerp( subray.birthTime, subray.endPropagationTime, segment.fraction0 ) - random1() * period;
const phase = lightningStrike.time - phase0;
const currentCycle = Math.floor( phase / period );
const childSubraySeed = random1() * ( currentCycle + 1 );
const isActive = phase % period <= dutyCycle * period;
let probability = 0;
if ( isActive ) {
probability = lightningStrike.subrayProbability;
// Distribution test: probability *= segment.fraction0 > 0.5 && segment.fraction0 < 0.9 ? 1 / 0.4 : 0;
}
if ( subray.recursion < lightningStrike.maxSubrayRecursion && lightningStrike.numSubrays < lightningStrike.maxSubrays && random1() < probability ) {
const childSubray = lightningStrike.addNewSubray();
const parentSeed = lightningStrike.randomGenerator.getSeed();
childSubray.seed = childSubraySeed;
lightningStrike.randomGenerator.setSeed( childSubraySeed );
childSubray.recursion = subray.recursion + 1;
childSubray.maxIterations = Math.max( 1, subray.maxIterations - 1 );
childSubray.linPos0.set( random1(), random1(), random1() ).multiplyScalar( 1000 );
childSubray.linPos1.set( random1(), random1(), random1() ).multiplyScalar( 1000 );
childSubray.up0.copy( subray.up0 );
childSubray.up1.copy( subray.up1 );
childSubray.radius0 = segment.radius0 * lightningStrike.rayParameters.radius0Factor;
childSubray.radius1 = Math.min( lightningStrike.rayParameters.minRadius, segment.radius1 * lightningStrike.rayParameters.radius1Factor );
childSubray.birthTime = phase0 + ( currentCycle ) * period;
childSubray.deathTime = childSubray.birthTime + period * dutyCycle;
if ( ! lightningStrike.rayParameters.isEternal && subray.recursion == 0 ) {
childSubray.birthTime = Math.max( childSubray.birthTime, subray.birthTime );
childSubray.deathTime = Math.min( childSubray.deathTime, subray.deathTime );
}
childSubray.timeScale = subray.timeScale * 2;
childSubray.roughness = subray.roughness;
childSubray.straightness = subray.straightness;
childSubray.propagationTimeFactor = subray.propagationTimeFactor;
childSubray.vanishingTimeFactor = subray.vanishingTimeFactor;
lightningStrike.onSubrayCreation( segment, subray, childSubray, lightningStrike );
lightningStrike.randomGenerator.setSeed( parentSeed );
}
};
const vec1Pos = new Vector3();
const vec2Forward = new Vector3();
const vec3Side = new Vector3();
const vec4Up = new Vector3();
this.onSubrayCreation = function ( segment, parentSubray, childSubray, lightningStrike ) {
// Decide childSubray origin and destination positions (pos0 and pos1) and possibly other properties of childSubray
// Just use the default cone position generator
lightningStrike.subrayCylinderPosition( segment, parentSubray, childSubray, 0.5, 0.6, 0.2 );
};
this.subrayConePosition = function ( segment, parentSubray, childSubray, heightFactor, sideWidthFactor, minSideWidthFactor ) {
// Sets childSubray pos0 and pos1 in a cone
childSubray.pos0.copy( segment.pos0 );
vec1Pos.subVectors( parentSubray.pos1, parentSubray.pos0 );
vec2Forward.copy( vec1Pos ).normalize();
vec1Pos.multiplyScalar( segment.fraction0 + ( 1 - segment.fraction0 ) * ( random1() * heightFactor ) );
const length = vec1Pos.length();
vec3Side.crossVectors( parentSubray.up0, vec2Forward );
const angle = 2 * Math.PI * random1();
vec3Side.multiplyScalar( Math.cos( angle ) );
vec4Up.copy( parentSubray.up0 ).multiplyScalar( Math.sin( angle ) );
childSubray.pos1.copy( vec3Side ).add( vec4Up ).multiplyScalar( length * sideWidthFactor * ( minSideWidthFactor + random1() * ( 1 - minSideWidthFactor ) ) ).add( vec1Pos ).add( parentSubray.pos0 );
};
this.subrayCylinderPosition = function ( segment, parentSubray, childSubray, heightFactor, sideWidthFactor, minSideWidthFactor ) {
// Sets childSubray pos0 and pos1 in a cylinder
childSubray.pos0.copy( segment.pos0 );
vec1Pos.subVectors( parentSubray.pos1, parentSubray.pos0 );
vec2Forward.copy( vec1Pos ).normalize();
vec1Pos.multiplyScalar( segment.fraction0 + ( 1 - segment.fraction0 ) * ( ( 2 * random1() - 1 ) * heightFactor ) );
const length = vec1Pos.length();
vec3Side.crossVectors( parentSubray.up0, vec2Forward );
const angle = 2 * Math.PI * random1();
vec3Side.multiplyScalar( Math.cos( angle ) );
vec4Up.copy( parentSubray.up0 ).multiplyScalar( Math.sin( angle ) );
childSubray.pos1.copy( vec3Side ).add( vec4Up ).multiplyScalar( length * sideWidthFactor * ( minSideWidthFactor + random1() * ( 1 - minSideWidthFactor ) ) ).add( vec1Pos ).add( parentSubray.pos0 );
};
}
createSubray() {
return {
seed: 0,
maxIterations: 0,
recursion: 0,
pos0: new Vector3(),
pos1: new Vector3(),
linPos0: new Vector3(),
linPos1: new Vector3(),
up0: new Vector3(),
up1: new Vector3(),
radius0: 0,
radius1: 0,
birthTime: 0,
deathTime: 0,
timeScale: 0,
roughness: 0,
straightness: 0,
propagationTimeFactor: 0,
vanishingTimeFactor: 0,
endPropagationTime: 0,
beginVanishingTime: 0
};
}
createSegment() {
return {
iteration: 0,
pos0: new Vector3(),
pos1: new Vector3(),
linPos0: new Vector3(),
linPos1: new Vector3(),
up0: new Vector3(),
up1: new Vector3(),
radius0: 0,
radius1: 0,
fraction0: 0,
fraction1: 0,
positionVariationFactor: 0
};
}
getNewSegment() {
return this.raySegments[ this.currentSegmentIndex ++ ];
}
copy( source ) {
super.copy( source );
this.init( LightningStrike.copyParameters( {}, source.rayParameters ) );
return this;
}
clone() {
return new this.constructor( LightningStrike.copyParameters( {}, this.rayParameters ) );
}
}
// Ray states
LightningStrike.RAY_INITIALIZED = 0;
LightningStrike.RAY_UNBORN = 1;
LightningStrike.RAY_PROPAGATING = 2;
LightningStrike.RAY_STEADY = 3;
LightningStrike.RAY_VANISHING = 4;
LightningStrike.RAY_EXTINGUISHED = 5;
LightningStrike.COS30DEG = Math.cos( 30 * Math.PI / 180 );
LightningStrike.SIN30DEG = Math.sin( 30 * Math.PI / 180 );
export { LightningStrike };