JavaFX | Point3D 类

Point3D类是 JavaFX 的一部分。此类定义 3D 空间中的 3 维点。 Point3D 类通过其 x、y、z 坐标表示 3D 点。

类的构造函数是：

• Point3D(double x, double y, double z) ：使用指定坐标创建一个 Point3D 对象。

常用方法：

Method	Explanation
distance(double x, double y, double z)	Calculates the distance between this point and the specified point
distance(Point3D p)	Calculates the distance between this point and the specified Point3D object
equals(java.lang.Object o)	Returns a hash code value for the point.
getX()	Returns the x coordinate
getY()	Returns the y coordinate
getZ()	Returns the z coordinate
hashCode()	Returns a hash code for this Point3D object.

下面的程序将说明 Point3D 类的使用：

1. Java程序创建一个 Point3D 对象并显示它的坐标并找到它与原点的距离：在这个程序中，我们通过传递它的 x、y、z 坐标作为参数来创建一个名为 point3d_1 的 Point3D 对象。我们使用getX() 、 getY() 、 getZ()函数获取 x、y、z 参数并显示它。我们还计算点到原点的距离并显示它。

Java

// Java program to create a point 3D
// object and display its coordinates
// and find its distance from origin
import javafx.geometry.Point3D;
 
public class Point3D_1 {
 
    // Main Method
    public static void main(String args[])
    {
 
        // Create a point3D object
        Point3D point3d_1 = new Point3D(20.0f, 50.0f, 70.0f);
 
        double x, y, z;
 
        // get the coordinates of the point
        x = point3d_1.getX();
        y = point3d_1.getY();
        z = point3d_1.getZ();
 
        // display the coordinates of the point
        System.out.println("x coordinate = " + x
                            + ", y coordinate = "
                            + y + ", z coordinate = " + z);
 
        // print its distance from origin
        System.out.println("Distance From Origin = "
                     + point3d_1.distance(0, 0, 0));
    }
}

输出：

x coordinate = 20.0, y coordinate = 50.0, z coordinate = 70.0
Distance From Origin = 88.31760866327846

2. Java程序创建 3 个 Point3D 对象并显示它们的坐标和到原点的距离，并检查 3 个点中哪一个相似以及它们在两点之间的距离：在这个程序中，我们通过传递创建 3 个 Point3D 对象，命名为 point3d_1、point3d_2、point3d_3它的 x、y、z 坐标作为参数。我们使用getX() 、 getY() 、 getZ()函数获取 x、y、z 参数并显示它。我们还计算点到原点的距离，并为三个点中的每一个显示它。我们还使用equals()函数显示任意两点是否相等，并使用 distance函数显示两点之间的距离。

Java

// Java program to create 3 Point3D objects and
// display their coordinates and distance from
// origin and check which of the 3 points are
// similar and their distances between two points
import javafx.geometry.Point3D;
 
public class Point3D_2 {
 
    // Main Method
    public static void main(String args[])
    {
 
        // create three point3D objects
        Point3D point3d_1 = new Point3D(20.0f, 50.0f, 70.0f);
        Point3D point3d_2 = new Point3D(20.0f, 50.0f, 70.0f);
        Point3D point3d_3 = new Point3D(200.0f, 20.0f, 90.0f);
 
        // display the coordinates of the 3 points
        display(point3d_1);
        display(point3d_2);
        display(point3d_3);
 
        // check whether any point is equal to other or not
        System.out.println("Point 1 equals point 2 = "
                       + point3d_1.equals(point3d_2));
 
        System.out.println("Point 2 equals point 3 = "
                       + point3d_2.equals(point3d_3));
 
        System.out.println("Point 3 equals point 1 = "
                        + point3d_3.equals(point3d_1));
 
        // distance between two points
        System.out.println("Distance between point 1 and point 2 = "
                                  + point3d_1.distance(point3d_2));
 
        System.out.println("Distance between point 2 and point 3 = "
                                   + point3d_2.distance(point3d_3));
 
        System.out.println("Distance between point 3 and point 1 = "
                                  + point3d_3.distance(point3d_1));
    }
 
    // Display Method
    public static void display(Point3D point3d)
    {
 
        double x, y, z;
 
        // get the coordinates of the point
        x = point3d.getX();
        y = point3d.getY();
        z = point3d.getZ();
 
        // display the coordinates of the point
        System.out.println("x coordinate = " + x
                           + ", y coordinate = "
                           + y + ", z coordinate = " + z);
 
        // print its distance from origin
        System.out.println("Distance From Origin = " +
                            point3d.distance(0, 0, 0));
    }
}

输出：

x coordinate = 20.0, y coordinate = 50.0, z coordinate = 70.0
Distance From Origin = 88.31760866327846
x coordinate = 20.0, y coordinate = 50.0, z coordinate = 70.0
Distance From Origin = 88.31760866327846
x coordinate = 200.0, y coordinate = 20.0, z coordinate = 90.0
Distance From Origin = 220.22715545545242
Point 1 equals point 2 = true
Point 2 equals point 3 = false
Point 3 equals point 1 = false
Distance between point 1 and point 2 = 0.0
Distance between point 2 and point 3 = 183.5755975068582
Distance between point 3 and point 1 = 183.5755975068582

注意：上述程序可能无法在在线 IDE 中运行。请使用离线编译器。

参考： https://docs.oracle.com/javafx/2/api/javafx/geometry/Point3D.html