在javaFX中围绕枢轴旋转对象

Question

我正试图在javaFX中创建一个魔方，但我很难旋转面。到目前为止，我只是将一张脸上的9个立方体添加到一组中，并将其旋转90度，以使整张脸以正确的方式旋转，但这种方法似乎不适用于多次旋转。

相反，我想围绕每个面的中心的枢轴点旋转每个立方体。为此，我尝试使用pivot参数中内置的Rotate类，但它似乎对旋转没有影响。以下是我用来旋转正面的函数的简化版本，其中2D阵列正面包含正面中从左上到右下的所有立方体：

public void rotate() {
Rotate r = new Rotate(45, 0, 0, -100, Rotate.Z_AXIS);
for (int x = 0; x < 3; x++) {
for (int y = 0; y < 3; y++) {
frontFace[x][y].getCube().getTransforms().add(r);
}
}
}   

这会产生以下结果(我将其旋转了45度，这样更容易看到(：

当前旋转

而我希望它像这样旋转：

理想旋转

这是我使用javaFX的第一个项目，如果有任何帮助，我们将不胜感激！到目前为止，完整的项目可以在这里找到：

https://gofile.io/d/KidwKh

编辑：我被要求包括一个最小的、可复制的例子，所以我试图将这个问题浓缩成一个类，希望不会混淆，下面是代码：

import javafx.application.Application;
import javafx.geometry.Point3D;
import javafx.scene.AmbientLight;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.DrawMode;
import javafx.scene.shape.MeshView;
import javafx.scene.shape.TriangleMesh;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
public class Example extends Application {

public static final float X_RED     = 0.5f / 7f;
public static final float X_GREEN   = 1.5f / 7f;
public static final float X_BLUE    = 2.5f / 7f;
public static final float X_YELLOW  = 3.5f / 7f;
public static final float X_ORANGE  = 4.5f / 7f;
public static final float X_WHITE   = 5.5f / 7f;
public static final float X_GRAY    = 6.5f / 7f;

public static int red = 0;
public static int green = 1;
public static int blue = 2;
public static int yellow = 3;
public static int orange = 4;
public static int white = 5;
public static int grey = 6;

public static int WIDTH = 1400;
public static int HEIGHT = 800;

private static final SmartGroup MainCubeGroup = new SmartGroup();
private static PhongMaterial mat = new PhongMaterial();

MeshView[][] frontFace = new MeshView[3][3];
@Override
public void start(Stage primaryStage) {
ViewCamera camera = new ViewCamera(MainCubeGroup);
mat.setDiffuseMap(new Image(getClass().getResourceAsStream("pallete.png")));
MainCubeGroup.getChildren().addAll(new AmbientLight(Color.WHITE));
Scene scene = new Scene(MainCubeGroup, WIDTH, HEIGHT, true);
//creates just frontFace of cube
frontFace[0][0] = createCube(new Point3D(-100, -100, -100), new int[]{blue, grey, white, grey, red, grey});
frontFace[0][1] = createCube(new Point3D(0, -100, -100),  new int[]{blue, grey, white, grey, grey, grey});
frontFace[0][2] = createCube(new Point3D(100, -100, -100), new int[] {blue, green, white, grey, grey, grey});
frontFace[1][0] = createCube(new Point3D(-100, 0, -100), new int[]{blue, grey, grey, grey, red, grey});
frontFace[1][1] = createCube(new Point3D(0, 0, -100), new int[]{blue, grey, grey, grey, grey, grey});
frontFace[1][2] = createCube(new Point3D(100, 0, -100),  new int[]{blue, green, grey, grey, grey, grey});
frontFace[2][0] = createCube(new Point3D(-100, 100, -100), new int[]{blue, grey, grey, grey, red, yellow});
frontFace[2][1] = createCube(new Point3D(0, 100, -100), new int[]{blue, grey, grey, grey, grey, yellow});
frontFace[2][2] = createCube(new Point3D(100, 100, -100),  new int[]{blue, green, grey, grey, grey, yellow});

rotate(45);

scene.setFill(Color.BLANCHEDALMOND);
scene.setCamera(camera);
primaryStage.setTitle("DDD");
primaryStage.setScene(scene);
MainCubeGroup.translateXProperty().set(WIDTH / 2);
MainCubeGroup.translateYProperty().set(HEIGHT / 2);
primaryStage.show();
camera.initMouseControl(scene, primaryStage);
}

public static void main(String[] args) {launch(args);}

public void rotate(int angle) {
Rotate r = new Rotate(angle, 0, 0, -100, Rotate.Z_AXIS);
for (int x = 0; x < 3; x++) {
for (int y = 0; y < 3; y++) {
frontFace[x][y].getTransforms().add(r);
}
}
}

public static MeshView createCube(Point3D position, int[] face){
int sideLength = 90;
TriangleMesh meshCube = new TriangleMesh();
meshCube.getTexCoords().addAll(
X_RED, 0.5f,
X_GREEN, 0.5f,
X_BLUE, 0.5f,
X_YELLOW, 0.5f,
X_ORANGE, 0.5f,
X_WHITE, 0.5f,
X_GRAY, 0.5f
);
meshCube.getPoints().addAll(
sideLength/2,  sideLength/2,  sideLength/2,  //point0
sideLength/2, -sideLength/2,  sideLength/2,  //point1
sideLength/2,  sideLength/2, -sideLength/2,  //point2
sideLength/2, -sideLength/2, -sideLength/2,  //point3
-sideLength/2,  sideLength/2,  sideLength/2, //point4
-sideLength/2, -sideLength/2,  sideLength/2, //point5
-sideLength/2,  sideLength/2, -sideLength/2, //point6
-sideLength/2, -sideLength/2, -sideLength/2  //point7
);
//textures
meshCube.getFaces().addAll(
2,face[0],3,face[0],6,face[0],      // F
3,face[0],7,face[0],6,face[0],
0,face[1],1,face[1],2,face[1],      // R
2,face[1],1,face[1],3,face[1],
1,face[2],5,face[2],3,face[2],      // U
5,face[2],7,face[2],3,face[2],
0,face[3],4,face[3],1,face[3],      // B
4,face[3],5,face[3],1,face[3],
4,face[4],6,face[4],5,face[4],      // L
6,face[4],7,face[4],5,face[4],
0,face[5],2,face[5],4,face[5],      // D
2,face[5],6,face[5],4,face[5]
);
MeshView cube = new MeshView(meshCube);
cube.setDrawMode(DrawMode.FILL);
cube.setMaterial(mat);
cube.setTranslateX(position.getX());
cube.setTranslateY(position.getY());
cube.setTranslateZ(position.getZ());
MainCubeGroup.getChildren().add(cube);
return cube;
}
}

这是代码中使用的图片pallete.png，如果你想要颜色的话，尽管我认为它与问题无关：托盘.png

谢谢。

Answer 1

将旋转对象r附加到frontFace节点时，每个这样的节点都会解释该节点自己的坐标系中旋转对象的坐标。每个立方体在其自己的坐标系中将其中心定义为(0，0，-100(，因此围绕该轴心点旋转会使立方体围绕其自己的中心旋转。

您需要的是使所有frontFace节点围绕同一坐标系(其父组的坐标系(中的单个轴心点旋转。

然后，可以使用parentToLocal方法将该轴心点重复转换为每个frontFace的坐标系，并基于该"局部"轴心点应用新的"旋转"实例。

public void rotate(int angle) {
// These coordinates are in the parent Group's coordinate system.
Point3D pivot = new Point3D(0, 0, -100);
for (int x = 0; x < 3; x++) {
for (int y = 0; y < 3; y++) {
Node cube = frontFace[x][y];
Point3D localPivot = cube.parentToLocal(pivot);
Rotate r = new Rotate(angle,
localPivot.getX(), localPivot.getY(), localPivot.getZ(),
Rotate.Z_AXIS);
cube.getTransforms().add(r);
}
}
}