JavaFX-Sample of how to animate Node in and out of Scene.

AnimateNodeIn.java

package application;

import java.util.function.Supplier;

import javafx.animation.Animation;
import javafx.animation.FadeTransition;
import javafx.animation.Interpolator;
import javafx.animation.RotateTransition;
import javafx.animation.ScaleTransition;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.KeyCode;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;

public class AnimateNodeIn extends Application {

  private static final int STAGE_WIDTH = 800;
  private static final int STAGE_HEIGHT = 600;

  @Override
  public void start(final Stage primaryStage) {

    final Group root = new Group();
    final Scene scene = new Scene(root, STAGE_WIDTH, STAGE_HEIGHT, Color.DARKGRAY);


    scene.setOnMouseClicked(click -> {
      final Button randomButton = new Button("Click me to remove me, yo!");
      randomButton.relocate(Math.random() * STAGE_WIDTH, Math.random() * STAGE_HEIGHT);
      randomButton.setFocusTraversable(false);
      addFadingIn(randomButton, root);
      randomButton.setOnAction(action -> {
        removeFadingOut(randomButton, root);
      });
    });

    scene.setOnKeyPressed(keyPress -> {
      if (keyPress.getCode().equals(KeyCode.ENTER)) {
        final Rectangle rectangle =
            new Rectangle(Math.random() * 400, Math.random() * 505, Color.rgb(
                (int) (Math.random() * 255), (int) (Math.random() * 255),
                (int) (Math.random() * 255)));
        rectangle.relocate(Math.random() * STAGE_WIDTH, Math.random() * STAGE_HEIGHT);
        addAnimating(rectangle, root, () -> {
          final RotateTransition animation = new RotateTransition(Duration.millis(500), rectangle);
          animation.setByAngle(Math.random() * 90);
          return animation;
        });

        rectangle.setOnMouseClicked(click -> {
          click.consume();
          removeAnimating(rectangle, root, () -> {
            final ScaleTransition scaleTransition =
                new ScaleTransition(Duration.millis(550), rectangle);
            scaleTransition.setToX(0);
            scaleTransition.setToY(0);
            return scaleTransition;
          });
        });
      }
    });

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

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

  public static void addFadingIn(final Node node, final Group parent) {
    final FadeTransition transition = new FadeTransition(Duration.millis(250), node);
    transition.setFromValue(0);
    transition.setToValue(1);
    transition.setInterpolator(Interpolator.EASE_IN);
    parent.getChildren().add(node);
    transition.play();
  }

  public static void removeFadingOut(final Node node, final Group parent) {
    if (parent.getChildren().contains(node)) {
      final FadeTransition transition = new FadeTransition(Duration.millis(250), node);
      transition.setFromValue(node.getOpacity());
      transition.setToValue(0);
      transition.setInterpolator(Interpolator.EASE_BOTH);
      transition.setOnFinished(finishHim -> {
        parent.getChildren().remove(node);
      });
      transition.play();
    }
  }

  public static void addAnimating(final Node node, final Group parent,
      final Supplier<Animation> animationCreator) {
    parent.getChildren().add(node);
    animationCreator.get().play();
  }

  public static void removeAnimating(final Node node, final Group parent,
      final Supplier<Animation> animationCreator) {
    if (parent.getChildren().contains(node)) {
      final Animation animation = animationCreator.get();
      animation.setOnFinished(finishHim -> {
        parent.getChildren().remove(node);
      });
      animation.play();

    }
  }
}