Issue
I created a star plotting application to plot labels for a 3d star plotter so that the labels are mapped local to scene. I wanted to do this so that whenever I rotate the starfield, the labels are always facing forward and don't rotate with the individual stars (annoying because they can't be read).
Now this works very well until I added a control panel above it. In the application below, if the control panel is not present, then labels track with the position of the stars. But with the control panel, the labels are y-offset by the size of the control panel height.
The issue is that the "mousePosY = me.getSceneY();" returns the mouse position of the scene itself and not the defined subScene. I had thought that the "subScene.setOnMouseDragged((MouseEvent me) -> {" would have given me the position of the mouse relative to the subScene and not the scene.
Is there any way to fix this so that the returned X,Y position is for the subScene only?
The following code is a very cutdown version of my application that shows the actual issue itself.
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.geometry.Point3D;
import javafx.scene.*;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Background;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Sphere;
import javafx.scene.text.Font;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.Translate;
import javafx.stage.Stage;
import lombok.extern.slf4j.Slf4j;
import java.util.HashMap;
import java.util.Random;
import static org.fxyz3d.geometry.MathUtils.clamp;
/**
* example for flat labels
*/
@Slf4j
public class StarFieldExample extends Application {
public static final int SCALE_X = 510;
public static final int SCALE_Y = 540;
public static final int SCALE_Z = 0;
final double sceneWidth = 600;
final double sceneHeight = 600;
private double mousePosX;
private double mousePosY;
private double mouseOldX;
private double mouseOldY;
private double mouseDeltaX;
private double mouseDeltaY;
private final Font font = new Font("arial", 10);
// We'll use custom Rotate transforms to manage the coordinate conversions
private final Rotate rotateX = new Rotate(0, Rotate.X_AXIS);
private final Rotate rotateY = new Rotate(0, Rotate.Y_AXIS);
private final Rotate rotateZ = new Rotate(0, Rotate.Z_AXIS);
private final Group root = new Group();
private final Group world = new Group(); //all 3D nodes in scene
private final Group labelGroup = new Group(); //all generic 3D labels
//All shapes and labels linked via hash for easy update during camera movement
private final HashMap<Node, Label> shape3DToLabel = new HashMap<>();
private SubScene subScene;
////// support
private final Random random = new Random();
private final static double RADIUS_MAX = 7;
private final static double X_MAX = 300;
private final static double Y_MAX = 300;
private final static double Z_MAX = 300;
private final Label scaleLabel = new Label("Scale: 5 ly");
public Pane createStarField() {
// attach our custom rotation transforms so we can update the labels dynamically
world.getTransforms().addAll(rotateX, rotateY, rotateZ);
subScene = new SubScene(world, sceneWidth, sceneHeight, true, SceneAntialiasing.BALANCED);
subScene.setFill(Color.BLACK);
PerspectiveCamera camera = new PerspectiveCamera(true);
camera.setNearClip(0.1);
camera.setFarClip(10000.0);
camera.setTranslateZ(-1000);
subScene.setCamera(camera);
Group sceneRoot = new Group(subScene);
sceneRoot.getChildren().add(labelGroup);
generateRandomStars(5);
handleMouseEvents();
// add to the 2D portion of this component
Pane pane = new Pane();
pane.setPrefSize(sceneWidth, sceneHeight);
pane.setMaxSize(Pane.USE_COMPUTED_SIZE, Pane.USE_COMPUTED_SIZE);
pane.setMinSize(Pane.USE_COMPUTED_SIZE, Pane.USE_COMPUTED_SIZE);
pane.setBackground(Background.EMPTY);
pane.getChildren().add(sceneRoot);
pane.setPickOnBounds(true);
subScene.widthProperty().bind(pane.widthProperty());
subScene.heightProperty().bind(pane.heightProperty());
Platform.runLater(this::updateLabels);
return (pane);
}
private void handleMouseEvents() {
subScene.setOnMousePressed((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseOldX = me.getSceneX();
mouseOldY = me.getSceneY();
}
);
subScene.setOnMouseDragged((MouseEvent me) -> {
mouseOldX = mousePosX;
mouseOldY = mousePosY;
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseDeltaX = (mousePosX - mouseOldX);
mouseDeltaY = (mousePosY - mouseOldY);
double modifier = 5.0;
double modifierFactor = 0.1;
if (me.isPrimaryButtonDown()) {
if (me.isAltDown()) { //roll
rotateZ.setAngle(((rotateZ.getAngle() + mouseDeltaX * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180); // +
} else {
rotateY.setAngle(((rotateY.getAngle() + mouseDeltaX * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180); // +
rotateX.setAngle(
clamp(
(((rotateX.getAngle() - mouseDeltaY * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180),
-60,
60
)
); // -
}
}
updateLabels();
}
);
}
public void generateRandomStars(int numberStars) {
for (int i = 0; i < numberStars; i++) {
double radius = random.nextDouble() * RADIUS_MAX;
Color color = randomColor();
double x = random.nextDouble() * X_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
double y = random.nextDouble() * Y_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
double z = random.nextDouble() * Z_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
String labelText = "Star " + i;
boolean fadeFlag = random.nextBoolean();
createSphereLabel(radius, x, y, z, color, labelText, fadeFlag);
}
//Add to hashmap so updateLabels() can manage the label position
scaleLabel.setFont(new Font("Arial", 15));
scaleLabel.setTextFill(Color.WHEAT);
scaleLabel.setTranslateX(SCALE_X);
scaleLabel.setTranslateY(SCALE_Y);
scaleLabel.setTranslateZ(SCALE_Z);
labelGroup.getChildren().add(scaleLabel);
log.info("shapes:{}", shape3DToLabel.size());
}
private Color randomColor() {
int r = random.nextInt(255);
int g = random.nextInt(255);
int b = random.nextInt(255);
return Color.rgb(r, g, b);
}
private void createSphereLabel(double radius, double x, double y, double z, Color color, String labelText, boolean fadeFlag) {
Sphere sphere = new Sphere(radius);
sphere.setTranslateX(x);
sphere.setTranslateY(y);
sphere.setTranslateZ(z);
sphere.setMaterial(new PhongMaterial(color));
//add our nodes to the group that will later be added to the 3D scene
world.getChildren().add(sphere);
Label label = new Label(labelText);
label.setTextFill(color);
label.setFont(font);
labelGroup.getChildren().add(label);
//Add to hashmap so updateLabels() can manage the label position
shape3DToLabel.put(sphere, label);
}
private void updateLabels() {
shape3DToLabel.forEach((node, label) -> {
Point3D coordinates = node.localToScene(Point3D.ZERO, true);
//Clipping Logic
//if coordinates are outside of the scene it could
//stretch the screen so don't transform them
double x = coordinates.getX();
double y = coordinates.getY();
// is it left of the view?
if (x < 0) {
x = 0;
}
// is it right of the view?
if ((x + label.getWidth() + 5) > subScene.getWidth()) {
x = subScene.getWidth() - (label.getWidth() + 5);
}
// is it above the view?
if (y < 0) {
y = 0;
}
// is it below the view
if ((y + label.getHeight()) > subScene.getHeight()) {
y = subScene.getHeight() - (label.getHeight() + 5);
}
//update the local transform of the label.
label.getTransforms().setAll(new Translate(x, y));
});
scaleLabel.setTranslateX(SCALE_X);
scaleLabel.setTranslateY(SCALE_Y);
scaleLabel.setTranslateZ(SCALE_Z);
}
//////////////////////////////////
@Override
public void start(Stage primaryStage) throws Exception {
Pane controls = createControls();
Pane pane = createStarField();
VBox vBox = new VBox(
controls,
pane
);
root.getChildren().add(vBox);
Scene scene = new Scene(root, sceneWidth, sceneHeight - 40);
primaryStage.setTitle("2D Labels over 3D SubScene");
primaryStage.setScene(scene);
primaryStage.show();
}
private VBox createControls() {
VBox controls = new VBox(10, new Button("Button"));
controls.setPadding(new Insets(10));
return controls;
}
public static void main(String[] args) {
launch(args);
}
}
Solution
I broke this down into a simpler problem relating mouse offset, solved that, and then worked that solution into here.
The key issue is that I assumed that the mouse event (x,y) positions would be zero offset to the SubScene, and in reality, they are relative to the containing scene. I had to calculate the bounds of the component relative to the parent. Having the actual location of the SubScene in the layout of the larger application allows me to calculate the corrected (x,y) positions.
Here is the answer:
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Bounds;
import javafx.geometry.Insets;
import javafx.geometry.Point3D;
import javafx.scene.*;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Background;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Sphere;
import javafx.scene.text.Font;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.Translate;
import javafx.stage.Stage;
import lombok.extern.slf4j.Slf4j;
import org.jetbrains.annotations.NotNull;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import static org.fxyz3d.geometry.MathUtils.clamp;
/**
* example for flat labels
*/
@Slf4j
public class StarFieldExample extends Application {
public static final int SCALE_X = 510;
public static final int SCALE_Y = 540;
public static final int SCALE_Z = 0;
final double sceneWidth = 600;
final double sceneHeight = 600;
private double mousePosX;
private double mousePosY;
private double mouseOldX;
private double mouseOldY;
private double mouseDeltaX;
private double mouseDeltaY;
private final Font font = new Font("arial", 10);
// We'll use custom Rotate transforms to manage the coordinate conversions
private final Rotate rotateX = new Rotate(0, Rotate.X_AXIS);
private final Rotate rotateY = new Rotate(0, Rotate.Y_AXIS);
private final Rotate rotateZ = new Rotate(0, Rotate.Z_AXIS);
private final Group root = new Group();
private final Group world = new Group(); //all 3D nodes in scene
private final Group labelGroup = new Group(); //all generic 3D labels
//All shapes and labels linked via hash for easy update during camera movement
private final Map<Node, Label> shape3DToLabel = new HashMap<>();
private SubScene subScene;
////// support
private final Random random = new Random();
private final static double RADIUS_MAX = 7;
private final static double X_MAX = 300;
private final static double Y_MAX = 300;
private final static double Z_MAX = 300;
Pane pane;
private final Label scaleLabel = new Label("Scale: 5 ly");
public Pane createStarField() {
PerspectiveCamera camera = setupPerspectiveCamera();
// attach our custom rotation transforms so we can update the labels dynamically
world.getTransforms().addAll(rotateX, rotateY, rotateZ);
subScene = new SubScene(world, sceneWidth, sceneHeight, true, SceneAntialiasing.BALANCED);
subScene.setFill(Color.BLACK);
subScene.setCamera(camera);
Group sceneRoot = new Group(subScene);
sceneRoot.getChildren().add(labelGroup);
generateRandomStars(5);
// add to the 2D portion of this component
pane = new Pane();
pane.setPrefSize(sceneWidth, sceneHeight);
pane.setMaxSize(Pane.USE_COMPUTED_SIZE, Pane.USE_COMPUTED_SIZE);
pane.setMinSize(Pane.USE_COMPUTED_SIZE, Pane.USE_COMPUTED_SIZE);
pane.setBackground(Background.EMPTY);
pane.getChildren().add(sceneRoot);
pane.setPickOnBounds(true);
subScene.widthProperty().bind(pane.widthProperty());
subScene.heightProperty().bind(pane.heightProperty());
Platform.runLater(this::updateLabels);
handleMouseEvents();
return (pane);
}
@NotNull
private PerspectiveCamera setupPerspectiveCamera() {
PerspectiveCamera camera = new PerspectiveCamera(true);
camera.setNearClip(0.1);
camera.setFarClip(10000.0);
camera.setTranslateZ(-1000);
return camera;
}
private void handleMouseEvents() {
subScene.setOnMousePressed((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseOldX = me.getSceneX();
mouseOldY = me.getSceneY();
}
);
subScene.setOnMouseDragged((MouseEvent me) -> {
mouseOldX = mousePosX;
mouseOldY = mousePosY;
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseDeltaX = (mousePosX - mouseOldX);
mouseDeltaY = (mousePosY - mouseOldY);
double modifier = 5.0;
double modifierFactor = 0.1;
if (me.isPrimaryButtonDown()) {
if (me.isAltDown()) { //roll
rotateZ.setAngle(((rotateZ.getAngle() + mouseDeltaX * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180); // +
} else {
rotateY.setAngle(((rotateY.getAngle() + mouseDeltaX * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180); // +
rotateX.setAngle(
clamp(
(((rotateX.getAngle() - mouseDeltaY * modifierFactor * modifier * 2.0) % 360 + 540) % 360 - 180),
-60,
60
)
); // -
}
}
updateLabels();
}
);
}
private void updateLabels() {
shape3DToLabel.forEach((node, label) -> {
Point3D coordinates = node.localToScene(Point3D.ZERO, true);
//Clipping Logic
//if coordinates are outside of the scene it could
//stretch the screen so don't transform them
double xs = coordinates.getX();
double ys = coordinates.getY();
Bounds ofParent = pane.getBoundsInParent();
double x = xs - ofParent.getMinX();
double y = ys - ofParent.getMinY();
// is it left of the view?
if (x < 0) {
x = 0;
}
// is it right of the view?
if ((x + label.getWidth() + 5) > subScene.getWidth()) {
x = subScene.getWidth() - (label.getWidth() + 5);
}
// is it above the view?
if (y < 0) {
y = 0;
}
// is it below the view
if ((y + label.getHeight()) > subScene.getHeight()) {
y = subScene.getHeight() - (label.getHeight() + 5);
}
//update the local transform of the label.
label.getTransforms().setAll(new Translate(x, y));
});
scaleLabel.setTranslateX(SCALE_X);
scaleLabel.setTranslateY(SCALE_Y);
scaleLabel.setTranslateZ(SCALE_Z);
}
public void generateRandomStars(int numberStars) {
for (int i = 0; i < numberStars; i++) {
double radius = random.nextDouble() * RADIUS_MAX;
Color color = randomColor();
double x = random.nextDouble() * X_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
double y = random.nextDouble() * Y_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
double z = random.nextDouble() * Z_MAX * 2 / 3 * (random.nextBoolean() ? 1 : -1);
String labelText = "Star " + i;
boolean fadeFlag = random.nextBoolean();
createSphereLabel(radius, x, y, z, color, labelText, fadeFlag);
}
//Add to hashmap so updateLabels() can manage the label position
scaleLabel.setFont(new Font("Arial", 15));
scaleLabel.setTextFill(Color.WHEAT);
scaleLabel.setTranslateX(SCALE_X);
scaleLabel.setTranslateY(SCALE_Y);
scaleLabel.setTranslateZ(SCALE_Z);
labelGroup.getChildren().add(scaleLabel);
log.info("shapes:{}", shape3DToLabel.size());
}
private Color randomColor() {
int r = random.nextInt(255);
int g = random.nextInt(255);
int b = random.nextInt(255);
return Color.rgb(r, g, b);
}
private void createSphereLabel(double radius, double x, double y, double z, Color color, String labelText, boolean fadeFlag) {
Sphere sphere = new Sphere(radius);
sphere.setTranslateX(x);
sphere.setTranslateY(y);
sphere.setTranslateZ(z);
sphere.setMaterial(new PhongMaterial(color));
//add our nodes to the group that will later be added to the 3D scene
world.getChildren().add(sphere);
Label label = new Label(labelText);
label.setTextFill(color);
label.setFont(font);
labelGroup.getChildren().add(label);
//Add to hashmap so updateLabels() can manage the label position
shape3DToLabel.put(sphere, label);
}
//////////////////////////////////
@Override
public void start(Stage primaryStage) throws Exception {
Pane controls = createControls();
Pane pane = createStarField();
VBox vBox = new VBox(
controls,
pane
);
root.getChildren().add(vBox);
Scene scene = new Scene(root, sceneWidth, sceneHeight - 40);
primaryStage.setTitle("2D Labels over 3D SubScene");
primaryStage.setScene(scene);
primaryStage.show();
}
private VBox createControls() {
VBox controls = new VBox(10, new Button("Button"));
controls.setPadding(new Insets(10));
return controls;
}
public static void main(String[] args) {
launch(args);
}
}
Answered By - EvilJinious1
