getTangent method
dynamic
getTangent(
- dynamic t, [
- dynamic optionalTarget
override
Implementation
getTangent( t, [optionalTarget]) {
var tangent = optionalTarget ?? new Vector3() ;
var u = this.knots[ 0 ] + t * ( this.knots[ this.knots.length - 1 ] - this.knots[ 0 ] );
var ders = NURBSUtils.calcNURBSDerivatives( this.degree, this.knots, this.controlPoints, u, 1 );
tangent.copy( ders[ 1 ] ).normalize();
return tangent;
}