java - 重叠形状 - 错误的重叠形状行为

Question

简而言之 - 我有 2 个旋转矩形。在旋转(通过 Y 轴)时，它们应该相互重叠 - 不幸的是，尽管旋转了 180 度，但其中一个矩形“始终在前面”。如何解决该行为？看起来它与已添加到组中的矩形的顺序有关。最后添加的总是在前面。

场景:

    package drawing.scene;

import javafx.application.Application;
import javafx.geometry.Point3D;
import javafx.scene.Camera;
import javafx.scene.Group;
import javafx.scene.PerspectiveCamera;
import javafx.scene.Scene;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import drawing.objects.Clock;
import drawing.objects.Cube;

public class MyScene extends Application {

    private int sceneEdgeSize = 800;
    private int clolcSize = 400;

    @Override
    public void start(Stage primaryStage) throws Exception {
        Group g = new Group();
        g.setTranslateX((sceneEdgeSize - clolcSize) / 2f);
        g.setTranslateY((sceneEdgeSize - clolcSize) / 2f);

        final Cube c = new Cube(clolcSize);
        g.getChildren().add(c);
        Thread t = new Thread(new Runnable() {

            @Override
            public void run() {
                Rotate r = rotate(0, Rotate.Y_AXIS);
                c.getTransforms().add(r);
                double angle = 0.0;
                while (true) {

                    r.setAngle(angle += 2);
                    try {
                        Thread.sleep(25);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        });
        t.setDaemon(true);
        primaryStage.setScene(new Scene(g, sceneEdgeSize, sceneEdgeSize));
        PerspectiveCamera camera = new PerspectiveCamera();
        primaryStage.getScene().setCamera(camera);
        primaryStage.show();
        t.start();

    }

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

    public Rotate rotate(double angle, Point3D axis) {
        return new Rotate(angle, clolcSize / 2f, clolcSize / 2f, 0, axis);
    }

}

立方体类:

package drawing.objects;

import javafx.collections.ObservableList;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.shape.RectangleBuilder;
import javafx.scene.transform.Rotate;

public class Cube extends Group {

    private double edgeLength = 0;

    public Cube(double edgeLength) {
        super();
        this.edgeLength = edgeLength;
        create();
    }

    private void create() {
        final Rotate rx = new Rotate(0, Rotate.X_AXIS);
        final Rotate ry = new Rotate(0, Rotate.Y_AXIS);
        final Rotate rz = new Rotate(0, Rotate.Z_AXIS);

        this.getTransforms().addAll(rx, ry, rz);

        ObservableList<Node> children = this.getChildren();
        //@formatter:off

        Rectangle rect;

        rect = RectangleBuilder // face
                .create()
                .width(edgeLength-20)
                .height(edgeLength-20)
                .translateZ(edgeLength * 0.5)
//                  .translateY(edgeLength * 0.5)
                //  .translateX(-edgeLength * 0.5)
                .fill(Color.LIGHTGREEN)
                .build()
                ;
        children.add(rect);
        rect = RectangleBuilder // face
                .create()
                .width(edgeLength-20)
                .height(edgeLength-20)
                .translateZ(-edgeLength * 0.5)
//              .translateY(-edgeLength * 0.5)
            //  .translateX(-edgeLength * 0.5)
                .fill(Color.DARKGREEN)
                .build()
                ;
        children.add(rect);


        //@formatter:on
    }
}

Answer 1

你应该 switch depth buffering on in your scene .

这个问题中的代码大部分已经过时，并且部分错误:

1. JavaFX 3D work , 推荐使用Java 8 .
2. 要构建立方体，请使用 Box形状。
3. 对于其他几何类型，使用 Sphere , Cylinder或 MeshView .
4. 使用Point和 Ambient灯光照亮您的场景。
5. 申请Materials到您的 3D 对象以对其进行着色。
6. 使用Model importers导入复杂的网格模型。
7. Builders已弃用。
8. 为了处理动画，不建议生成另一个线程，而是使用 JavaFX animation package .
9. 对于您问题中的特定动画，RotateTransition是合适的动画。
10. 您的解决方案不是线程安全的。您不应在应用程序线程之外修改 Activity 场景图中节点的属性(例如，显示节点的变换属性)(改为使用 Platform.runLater)。
11. 您没有使用 depth buffering 创建场景设置为真。深度缓冲标志告诉 JavaFX 它应该对 3D 对象应用深度排序和剔除。

同时检查您的系统是否支持 JavaFX 3D:

System.out.println(
  "3D supported? " + 
  Platform.isSupported(ConditionalFeature.SCENE3D)
);

旋转立方体的 Java 8 3D 示例代码

这是一个用 Java 8 编码的旋转立方体。

import javafx.animation.*;
import javafx.application.Application;
import javafx.scene.*;
import javafx.scene.paint.*;
import javafx.scene.shape.Box;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import javafx.util.Duration;

public class RotatingCube extends Application {

    private static final double SCENE_SIZE = 300;
    private static final double BOX_EDGE_LENGTH = SCENE_SIZE / 2d;

    private static final Color BOX_COLOR     = Color.DARKGREEN;
    private static final Color AMBIENT_COLOR = Color.rgb(30, 30, 30);
    private static final Color LIGHT_COLOR   = Color.WHITE;

    private static final Duration ROTATION_DURATION = Duration.seconds(4.5);

    @Override
    public void start(Stage stage) throws Exception {
        Scene scene = new Scene(
                new Group(
                        new AmbientLight(AMBIENT_COLOR),
                        createPointLight(),
                        createRotatingBox()
                ),
                SCENE_SIZE, SCENE_SIZE,
                true,
                SceneAntialiasing.BALANCED
        );
        scene.setFill(Color.MIDNIGHTBLUE.darker().darker().darker());
        scene.setCamera(new PerspectiveCamera());

        stage.setScene(scene);
        stage.show();
    }

    private PointLight createPointLight() {
        PointLight light = new PointLight(LIGHT_COLOR);
        light.setTranslateX( SCENE_SIZE / 2d);
        light.setTranslateY( SCENE_SIZE / 2d);
        light.setTranslateZ(-SCENE_SIZE);

        return light;
    }

    private Box createRotatingBox() {
        final Box box = new Box(BOX_EDGE_LENGTH, BOX_EDGE_LENGTH, BOX_EDGE_LENGTH);
        box.setTranslateX(SCENE_SIZE / 2d);
        box.setTranslateY(SCENE_SIZE / 2d);
        box.setTranslateZ(BOX_EDGE_LENGTH / 2d);
        box.setMaterial(new PhongMaterial(BOX_COLOR));

        rotateAroundYAxis(box);

        return box;
    }

    private void rotateAroundYAxis(Box box) {
        RotateTransition rotate = new RotateTransition(ROTATION_DURATION, box);
        rotate.setFromAngle(0);
        rotate.setToAngle(360);
        rotate.setAxis(Rotate.Y_AXIS);
        rotate.setCycleCount(RotateTransition.INDEFINITE);
        rotate.setInterpolator(Interpolator.LINEAR);
        rotate.play();
    }

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

}

两个旋转矩形的 Java 8 3D 示例代码

import javafx.animation.*;
import javafx.application.*;
import javafx.scene.*;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import javafx.util.Duration;

public class RotatingRectangles extends Application {

    private static final double SCENE_SIZE = 300;
    private static final double EDGE_LENGTH = SCENE_SIZE / 2d;

    private static final Duration ROTATION_DURATION = Duration.seconds(4.5);

    @Override
    public void start(Stage stage) throws Exception {
        System.out.println(
            "3D supported? " +
            Platform.isSupported(ConditionalFeature.SCENE3D)
        );

        Scene scene = new Scene(
                createRotatingShapes(),
                SCENE_SIZE, SCENE_SIZE,
                true,
                SceneAntialiasing.BALANCED
        );
        scene.setFill(Color.MIDNIGHTBLUE.darker().darker().darker());
        scene.setCamera(new PerspectiveCamera());

        stage.setScene(scene);
        stage.show();
    }

    private Group createRotatingShapes() {
        final Rectangle rect1 = new Rectangle(
            EDGE_LENGTH, EDGE_LENGTH,
            Color.LIGHTGREEN
        );
        rect1.setTranslateX(-EDGE_LENGTH / 2d);
        rect1.setTranslateY(-EDGE_LENGTH / 2d);
        rect1.setTranslateZ( EDGE_LENGTH / 2d);

        final Rectangle rect2 = new Rectangle(
            EDGE_LENGTH, EDGE_LENGTH,
            Color.DARKGREEN
        );
        rect2.setTranslateX(-EDGE_LENGTH / 2d);
        rect2.setTranslateY(-EDGE_LENGTH / 2d);
        rect2.setTranslateZ(-EDGE_LENGTH / 2d);

        final Group shapes = new Group(
            rect1, rect2
        );

        shapes.setTranslateX(SCENE_SIZE / 2d);
        shapes.setTranslateY(SCENE_SIZE / 2d);
        shapes.setTranslateZ(EDGE_LENGTH / 2d);

        rotateAroundYAxis(shapes);

        return shapes;
    }

    private void rotateAroundYAxis(Node node) {
        RotateTransition rotate = new RotateTransition(ROTATION_DURATION, node);
        rotate.setFromAngle(0);
        rotate.setToAngle(360);
        rotate.setAxis(Rotate.Y_AXIS);
        rotate.setCycleCount(RotateTransition.INDEFINITE);
        rotate.setInterpolator(Interpolator.LINEAR);
        rotate.play();
    }

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

}

在第一张图片中，深色矩形已经旋转到浅色矩形的前面。

在第一张图片中，浅色矩形已旋转到深色矩形前面。

因此您可以看到 JavaFX 系统正确显示场景中的深度排序形状。