53 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
		
		
			
		
	
	
			53 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
|  | import { | ||
|  | 	Vector4 | ||
|  | } from 'three'; | ||
|  | import * as NURBSUtils from '../curves/NURBSUtils.js'; | ||
|  | 
 | ||
|  | /** | ||
|  |  * NURBS surface object | ||
|  |  * | ||
|  |  * Implementation is based on (x, y [, z=0 [, w=1]]) control points with w=weight. | ||
|  |  **/ | ||
|  | 
 | ||
|  | class NURBSSurface { | ||
|  | 
 | ||
|  | 	constructor( degree1, degree2, knots1, knots2 /* arrays of reals */, controlPoints /* array^2 of Vector(2|3|4) */ ) { | ||
|  | 
 | ||
|  | 		this.degree1 = degree1; | ||
|  | 		this.degree2 = degree2; | ||
|  | 		this.knots1 = knots1; | ||
|  | 		this.knots2 = knots2; | ||
|  | 		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 ); | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	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 }; |