three 基础库
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import {
Curve,
Vector3
} from '../../../build/three.module.js';
/**
* A bunch of parametric curves
*
* Formulas collected from various sources
* http://mathworld.wolfram.com/HeartCurve.html
* http://mathdl.maa.org/images/upload_library/23/stemkoski/knots/page6.html
* http://en.wikipedia.org/wiki/Viviani%27s_curve
* http://mathdl.maa.org/images/upload_library/23/stemkoski/knots/page4.html
* http://www.mi.sanu.ac.rs/vismath/taylorapril2011/Taylor.pdf
* https://prideout.net/blog/old/blog/index.html@p=44.html
*/
// GrannyKnot
class GrannyKnot extends Curve {
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t = 2 * Math.PI * t;
const x = - 0.22 * Math.cos( t ) - 1.28 * Math.sin( t ) - 0.44 * Math.cos( 3 * t ) - 0.78 * Math.sin( 3 * t );
const y = - 0.1 * Math.cos( 2 * t ) - 0.27 * Math.sin( 2 * t ) + 0.38 * Math.cos( 4 * t ) + 0.46 * Math.sin( 4 * t );
const z = 0.7 * Math.cos( 3 * t ) - 0.4 * Math.sin( 3 * t );
return point.set( x, y, z ).multiplyScalar( 20 );
}
}
// HeartCurve
class HeartCurve extends Curve {
constructor( scale = 5 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t *= 2 * Math.PI;
const x = 16 * Math.pow( Math.sin( t ), 3 );
const y = 13 * Math.cos( t ) - 5 * Math.cos( 2 * t ) - 2 * Math.cos( 3 * t ) - Math.cos( 4 * t );
const z = 0;
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// Viviani's Curve
class VivianiCurve extends Curve {
constructor( scale = 70 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t = t * 4 * Math.PI; // normalized to 0..1
const a = this.scale / 2;
const x = a * ( 1 + Math.cos( t ) );
const y = a * Math.sin( t );
const z = 2 * a * Math.sin( t / 2 );
return point.set( x, y, z );
}
}
// KnotCurve
class KnotCurve extends Curve {
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t *= 2 * Math.PI;
const R = 10;
const s = 50;
const x = s * Math.sin( t );
const y = Math.cos( t ) * ( R + s * Math.cos( t ) );
const z = Math.sin( t ) * ( R + s * Math.cos( t ) );
return point.set( x, y, z );
}
}
// HelixCurve
class HelixCurve extends Curve {
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const a = 30; // radius
const b = 150; // height
const t2 = 2 * Math.PI * t * b / 30;
const x = Math.cos( t2 ) * a;
const y = Math.sin( t2 ) * a;
const z = b * t;
return point.set( x, y, z );
}
}
// TrefoilKnot
class TrefoilKnot extends Curve {
constructor( scale = 10 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t *= Math.PI * 2;
const x = ( 2 + Math.cos( 3 * t ) ) * Math.cos( 2 * t );
const y = ( 2 + Math.cos( 3 * t ) ) * Math.sin( 2 * t );
const z = Math.sin( 3 * t );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// TorusKnot
class TorusKnot extends Curve {
constructor( scale = 10 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const p = 3;
const q = 4;
t *= Math.PI * 2;
const x = ( 2 + Math.cos( q * t ) ) * Math.cos( p * t );
const y = ( 2 + Math.cos( q * t ) ) * Math.sin( p * t );
const z = Math.sin( q * t );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// CinquefoilKnot
class CinquefoilKnot extends Curve {
constructor( scale = 10 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const p = 2;
const q = 5;
t *= Math.PI * 2;
const x = ( 2 + Math.cos( q * t ) ) * Math.cos( p * t );
const y = ( 2 + Math.cos( q * t ) ) * Math.sin( p * t );
const z = Math.sin( q * t );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// TrefoilPolynomialKnot
class TrefoilPolynomialKnot extends Curve {
constructor( scale = 10 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t = t * 4 - 2;
const x = Math.pow( t, 3 ) - 3 * t;
const y = Math.pow( t, 4 ) - 4 * t * t;
const z = 1 / 5 * Math.pow( t, 5 ) - 2 * t;
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
function scaleTo( x, y, t ) {
const r = y - x;
return t * r + x;
}
// FigureEightPolynomialKnot
class FigureEightPolynomialKnot extends Curve {
constructor( scale = 1 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t = scaleTo( - 4, 4, t );
const x = 2 / 5 * t * ( t * t - 7 ) * ( t * t - 10 );
const y = Math.pow( t, 4 ) - 13 * t * t;
const z = 1 / 10 * t * ( t * t - 4 ) * ( t * t - 9 ) * ( t * t - 12 );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// DecoratedTorusKnot4a
class DecoratedTorusKnot4a extends Curve {
constructor( scale = 40 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
t *= Math.PI * 2;
const x = Math.cos( 2 * t ) * ( 1 + 0.6 * ( Math.cos( 5 * t ) + 0.75 * Math.cos( 10 * t ) ) );
const y = Math.sin( 2 * t ) * ( 1 + 0.6 * ( Math.cos( 5 * t ) + 0.75 * Math.cos( 10 * t ) ) );
const z = 0.35 * Math.sin( 5 * t );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// DecoratedTorusKnot4b
class DecoratedTorusKnot4b extends Curve {
constructor( scale = 40 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const fi = t * Math.PI * 2;
const x = Math.cos( 2 * fi ) * ( 1 + 0.45 * Math.cos( 3 * fi ) + 0.4 * Math.cos( 9 * fi ) );
const y = Math.sin( 2 * fi ) * ( 1 + 0.45 * Math.cos( 3 * fi ) + 0.4 * Math.cos( 9 * fi ) );
const z = 0.2 * Math.sin( 9 * fi );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// DecoratedTorusKnot5a
class DecoratedTorusKnot5a extends Curve {
constructor( scale = 40 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const fi = t * Math.PI * 2;
const x = Math.cos( 3 * fi ) * ( 1 + 0.3 * Math.cos( 5 * fi ) + 0.5 * Math.cos( 10 * fi ) );
const y = Math.sin( 3 * fi ) * ( 1 + 0.3 * Math.cos( 5 * fi ) + 0.5 * Math.cos( 10 * fi ) );
const z = 0.2 * Math.sin( 20 * fi );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
// DecoratedTorusKnot5c
class DecoratedTorusKnot5c extends Curve {
constructor( scale = 40 ) {
super();
this.scale = scale;
}
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
const fi = t * Math.PI * 2;
const x = Math.cos( 4 * fi ) * ( 1 + 0.5 * ( Math.cos( 5 * fi ) + 0.4 * Math.cos( 20 * fi ) ) );
const y = Math.sin( 4 * fi ) * ( 1 + 0.5 * ( Math.cos( 5 * fi ) + 0.4 * Math.cos( 20 * fi ) ) );
const z = 0.35 * Math.sin( 15 * fi );
return point.set( x, y, z ).multiplyScalar( this.scale );
}
}
const Curves = {
GrannyKnot: GrannyKnot,
HeartCurve: HeartCurve,
VivianiCurve: VivianiCurve,
KnotCurve: KnotCurve,
HelixCurve: HelixCurve,
TrefoilKnot: TrefoilKnot,
TorusKnot: TorusKnot,
CinquefoilKnot: CinquefoilKnot,
TrefoilPolynomialKnot: TrefoilPolynomialKnot,
FigureEightPolynomialKnot: FigureEightPolynomialKnot,
DecoratedTorusKnot4a: DecoratedTorusKnot4a,
DecoratedTorusKnot4b: DecoratedTorusKnot4b,
DecoratedTorusKnot5a: DecoratedTorusKnot5a,
DecoratedTorusKnot5c: DecoratedTorusKnot5c
};
export { Curves };