code: public void set(Vector3D v1, Vector3D v2) {
          this.MODE = LINES;
          this.x1 = v1.getX();
          this.y1 = v1.getY();
          this.z1 = v1.getZ();
          this.x2 = v2.getX();
          this.y2 = v2.getY();
          this.z2 = v2.getZ();
          calcG();
          dx[0] = x1 - this.x;
          dx[1] = x2 - this.x;
          dy[0] = y1 - this.y;
          dy[1] = y2 - this.y;
          dz[0] = z1 - this.z;
          dz[1] = z2 - this.z;
          if (dashed) calcDashedLine();
      }
docs: Sets the coordinates for the first and second point.
  
  @param v1 The coordinates for the first anchor point.
  @param v2 The coordinates for the first control point.