曲线增加获得最近点.

src/DatabaseServices/Curve.ts

@@ -39,4 +39,5 @@ export abstract class Curve extends Entity
     PtOnCurve(pt: Vector3): boolean { return; }
 
     GetOffsetCurves(offsetDist: number): Array<Curve> { return; }
+    GetClosestPointTo(pt: Vector3, extend: boolean): Vector3 { return; }
 }