Accueil / npm / three@0.186.1 / examples / jsm / curves / NURBSSurface.js
NURBSSurface.js
import {
Vector4
} from 'three';
import * as NURBSUtils from '../curves/NURBSUtils.js';
/**
* This class represents a NURBS surface.
*
* Implementation is based on `(x, y [, z=0 [, w=1]])` control points with `w=weight`.
*
* @three_import import { NURBSSurface } from 'three/addons/curves/NURBSSurface.js';
*/
class NURBSSurface {
/**
* Constructs a new NURBS surface.
*
* @param {number} degree1 - The first NURBS degree.
* @param {number} degree2 - The second NURBS degree.
* @param {Array<number>} knots1 - The first knots as a flat array of numbers.
* @param {Array<number>} knots2 - The second knots as a flat array of numbers.
* @param {Array<Array<Vector2|Vector3|Vector4>>} controlPoints - An array^2 holding control points.
*/
constructor( degree1, degree2, knots1, knots2, controlPoints ) {
/**
* The first NURBS degree.
*
* @type {number}
*/
this.degree1 = degree1;
/**
* The second NURBS degree.
*
* @type {number}
*/
this.degree2 = degree2;
/**
* The first knots as a flat array of numbers.
*
* @type {Array<number>}
*/
this.knots1 = knots1;
/**
* The second knots as a flat array of numbers.
*
* @type {Array<number>}
*/
this.knots2 = knots2;
/**
* An array holding arrays of control points.
*
* @type {Array<Array<Vector2|Vector3|Vector4>>}
*/
this.controlPoints = [];
const len1 = knots1.length - degree1 - 1;
const len2 = knots2.length - degree2 - 1;
// ensure Vector4 for control points
for ( let i = 0; i < len1; ++ i ) {
this.controlPoints[ i ] = [];
for ( let j = 0; j < len2; ++ j ) {
const point = controlPoints[ i ][ j ];
this.controlPoints[ i ][ j ] = new Vector4( point.x, point.y, point.z, point.w );
}
}
}
/**
* This method returns a vector in 3D space for the given interpolation factor. This vector lies on the NURBS surface.
*
* @param {number} t1 - The first interpolation factor representing the `u` position on the surface. Must be in the range `[0,1]`.
* @param {number} t2 - The second interpolation factor representing the `v` position on the surface. Must be in the range `[0,1]`.
* @param {Vector3} target - The target vector the result is written to.
*/
getPoint( t1, t2, target ) {
const u = this.knots1[ 0 ] + t1 * ( this.knots1[ this.knots1.length - 1 ] - this.knots1[ 0 ] ); // linear mapping t1->u
const v = this.knots2[ 0 ] + t2 * ( this.knots2[ this.knots2.length - 1 ] - this.knots2[ 0 ] ); // linear mapping t2->u
NURBSUtils.calcSurfacePoint( this.degree1, this.degree2, this.knots1, this.knots2, this.controlPoints, u, v, target );
}
}
export { NURBSSurface };