Dies ist das Repository meines kleinen Portfolios.
Im Hintergrund läuft eine Planetensimulation, geschrieben in JavaScript und Three.js.
Die zu sehenden Texturen stammen von:
https://www.solarsystemscope.com/textures/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
75 lines
1.8 KiB
75 lines
1.8 KiB
( function () { |
|
|
|
/** |
|
* NURBS curve object |
|
* |
|
* Derives from THREE.Curve, overriding getPoint and getTangent. |
|
* |
|
* Implementation is based on (x, y [, z=0 [, w=1]]) control points with w=weight. |
|
* |
|
**/ |
|
|
|
class NURBSCurve extends THREE.Curve { |
|
|
|
constructor( degree, knots |
|
/* array of reals */ |
|
, controlPoints |
|
/* array of Vector(2|3|4) */ |
|
, startKnot |
|
/* index in knots */ |
|
, endKnot |
|
/* index in knots */ |
|
) { |
|
|
|
super(); |
|
this.degree = degree; |
|
this.knots = knots; |
|
this.controlPoints = []; // Used by periodic NURBS to remove hidden spans |
|
|
|
this.startKnot = startKnot || 0; |
|
this.endKnot = endKnot || this.knots.length - 1; |
|
|
|
for ( let i = 0; i < controlPoints.length; ++ i ) { |
|
|
|
// ensure THREE.Vector4 for control points |
|
const point = controlPoints[ i ]; |
|
this.controlPoints[ i ] = new THREE.Vector4( point.x, point.y, point.z, point.w ); |
|
|
|
} |
|
|
|
} |
|
|
|
getPoint( t, optionalTarget = new THREE.Vector3() ) { |
|
|
|
const point = optionalTarget; |
|
const u = this.knots[ this.startKnot ] + t * ( this.knots[ this.endKnot ] - this.knots[ this.startKnot ] ); // linear mapping t->u |
|
// following results in (wx, wy, wz, w) homogeneous point |
|
|
|
const hpoint = THREE.NURBSUtils.calcBSplinePoint( this.degree, this.knots, this.controlPoints, u ); |
|
|
|
if ( hpoint.w !== 1.0 ) { |
|
|
|
// project to 3D space: (wx, wy, wz, w) -> (x, y, z, 1) |
|
hpoint.divideScalar( hpoint.w ); |
|
|
|
} |
|
|
|
return point.set( hpoint.x, hpoint.y, hpoint.z ); |
|
|
|
} |
|
|
|
getTangent( t, optionalTarget = new THREE.Vector3() ) { |
|
|
|
const tangent = optionalTarget; |
|
const u = this.knots[ 0 ] + t * ( this.knots[ this.knots.length - 1 ] - this.knots[ 0 ] ); |
|
const ders = THREE.NURBSUtils.calcNURBSDerivatives( this.degree, this.knots, this.controlPoints, u, 1 ); |
|
tangent.copy( ders[ 1 ] ).normalize(); |
|
return tangent; |
|
|
|
} |
|
|
|
} |
|
|
|
THREE.NURBSCurve = NURBSCurve; |
|
|
|
} )();
|
|
|