问题
My problems are:
- the below code is based on the "MolecularSampleApp" from the oracle tutorial site, but very much simplified. It only shows a box and a red sphere for orientation purpose. The sequence of rotations is around x-axis then y-axis and finally z-axis. Following rotations are apparently done in coordinate-axes that are rotated with the rotations before. (I checked that again and again with a cube and sequences of 90° rotations) So, when the user rotates the camera view with the mouse, this is very unintuitive, because the rotation behaviour changes after rotating around the vertical screen axis (because the horizontal axis will then be rotated too). Try it with my code below, or with the MolecularSampleApp - its the same unnatural feeling. Is there an easy way to get over this?
- But what I don't even understand is the behaviour when the mousePressed-code is performed: Here, the camera is always rotated in a FIXED system! The axes are NOT rotated with the camera, although its essentially the same code (except the rotation angle is of course not accumulated here). Anybody knows how is this possible?
package trafotest;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.scene.DepthTest;
import javafx.scene.Group;
import javafx.scene.PerspectiveCamera;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Box;
import javafx.scene.shape.Sphere;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.Translate;
import javafx.stage.Stage;
public class TrafoTest extends Application {
final Group root = new Group();
final XformWorld world = new XformWorld();
final PerspectiveCamera camera = new PerspectiveCamera(true);
final XformCamera cameraXform = new XformCamera();
private static final double CAMERA_INITIAL_DISTANCE = -1000;
private static final double CAMERA_NEAR_CLIP = 0.1;
private static final double CAMERA_FAR_CLIP = 10000.0;
double mousePosX, mousePosY, mouseOldX, mouseOldY, mouseDeltaX, mouseDeltaY;
@Override
public void start(Stage primaryStage) {
root.getChildren().add(world);
root.setDepthTest(DepthTest.ENABLE);
buildCamera();
buildBodySystem();
Scene scene = new Scene(root, 800, 600, true);
scene.setFill(Color.GREY);
handleMouse(scene);
primaryStage.setTitle("Transformationen");
primaryStage.setScene(scene);
primaryStage.show();
scene.setCamera(camera);
}
private void buildCamera() {
root.getChildren().add(cameraXform);
cameraXform.getChildren().add(camera);
camera.setNearClip(CAMERA_NEAR_CLIP);
camera.setFarClip(CAMERA_FAR_CLIP);
camera.setTranslateZ(CAMERA_INITIAL_DISTANCE);
}
private void buildBodySystem() {
PhongMaterial whiteMaterial = new PhongMaterial();
whiteMaterial.setDiffuseColor(Color.WHITE);
whiteMaterial.setSpecularColor(Color.LIGHTBLUE);
Box box = new Box(400, 200, 100);
box.setMaterial(whiteMaterial);
PhongMaterial redMaterial = new PhongMaterial();
redMaterial.setDiffuseColor(Color.DARKRED);
redMaterial.setSpecularColor(Color.RED);
Sphere sphere = new Sphere(5);
sphere.setMaterial(redMaterial);
sphere.setTranslateZ(-50.0);
world.getChildren().addAll(box);
world.getChildren().addAll(sphere);
}
private void handleMouse(Scene scene) {
scene.setOnMousePressed((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseOldX = me.getSceneX();
mouseOldY = me.getSceneY();
// this is done after clicking and the rotations are apearently
// performed in coordinates that are NOT rotated with the camera.
// (pls activate the two lines below for clicking)
//cameraXform.rx.setAngle(-90.0);
//cameraXform.ry.setAngle(180.0);
});
scene.setOnMouseDragged((MouseEvent me) -> {
mouseOldX = mousePosX;
mouseOldY = mousePosY;
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseDeltaX = (mousePosX - mouseOldX);
mouseDeltaY = (mousePosY - mouseOldY);
if (me.isPrimaryButtonDown()) {
// this is done when the mouse is dragged and each rotation is
// performed in coordinates, that are rotated with the camera.
cameraXform.ry.setAngle(cameraXform.ry.getAngle() + mouseDeltaX * 0.2);
cameraXform.rx.setAngle(cameraXform.rx.getAngle() - mouseDeltaY * 0.2);
}
});
}
public static void main(String[] args) {
launch(args);
}
}
class XformWorld extends Group {
final Translate t = new Translate(0.0, 0.0, 0.0);
final Rotate rx = new Rotate(0, 0, 0, 0, Rotate.X_AXIS);
final Rotate ry = new Rotate(0, 0, 0, 0, Rotate.Y_AXIS);
final Rotate rz = new Rotate(0, 0, 0, 0, Rotate.Z_AXIS);
public XformWorld() {
super();
this.getTransforms().addAll(t, rx, ry, rz);
}
}
class XformCamera extends Group {
final Translate t = new Translate(0.0, 0.0, 0.0);
final Rotate rx = new Rotate(0, 0, 0, 0, Rotate.X_AXIS);
final Rotate ry = new Rotate(0, 0, 0, 0, Rotate.Y_AXIS);
final Rotate rz = new Rotate(0, 0, 0, 0, Rotate.Z_AXIS);
public XformCamera() {
super();
this.getTransforms().addAll(t, rx, ry, rz);
}
}
回答1:
I found a solution that works for me, just in case someone else is interested too:
package trafotest;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.geometry.Point3D;
import javafx.scene.DepthTest;
import javafx.scene.Group;
import javafx.scene.PerspectiveCamera;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Box;
import javafx.scene.shape.Sphere;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.Transform;
import javafx.scene.transform.Translate;
import javafx.stage.Stage;
public class TrafoTest extends Application {
final Group root = new Group();
final XformWorld world = new XformWorld();
final PerspectiveCamera camera = new PerspectiveCamera(true);
final XformCamera cameraXform = new XformCamera();
private static final double CAMERA_INITIAL_DISTANCE = -1000;
private static final double CAMERA_NEAR_CLIP = 0.1;
private static final double CAMERA_FAR_CLIP = 10000.0;
double mousePosX, mousePosY, mouseOldX, mouseOldY, mouseDeltaX, mouseDeltaY;
double mouseFactorX, mouseFactorY;
@Override
public void start(Stage primaryStage) {
root.getChildren().add(world);
root.setDepthTest(DepthTest.ENABLE);
buildCamera();
buildBodySystem();
Scene scene = new Scene(root, 800, 600, true);
scene.setFill(Color.GREY);
handleMouse(scene);
primaryStage.setTitle("TrafoTest");
primaryStage.setScene(scene);
primaryStage.show();
scene.setCamera(camera);
mouseFactorX = 180.0 / scene.getWidth();
mouseFactorY = 180.0 / scene.getHeight();
}
private void buildCamera() {
root.getChildren().add(cameraXform);
cameraXform.getChildren().add(camera);
camera.setNearClip(CAMERA_NEAR_CLIP);
camera.setFarClip(CAMERA_FAR_CLIP);
camera.setTranslateZ(CAMERA_INITIAL_DISTANCE);
}
private void buildBodySystem() {
PhongMaterial whiteMaterial = new PhongMaterial();
whiteMaterial.setDiffuseColor(Color.WHITE);
whiteMaterial.setSpecularColor(Color.LIGHTBLUE);
Box box = new Box(400, 200, 100);
box.setMaterial(whiteMaterial);
PhongMaterial redMaterial = new PhongMaterial();
redMaterial.setDiffuseColor(Color.DARKRED);
redMaterial.setSpecularColor(Color.RED);
Sphere sphere = new Sphere(5);
sphere.setMaterial(redMaterial);
sphere.setTranslateX(200.0);
sphere.setTranslateY(-100.0);
sphere.setTranslateZ(-50.0);
world.getChildren().addAll(box);
world.getChildren().addAll(sphere);
}
private void handleMouse(Scene scene) {
scene.setOnMousePressed((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseOldX = me.getSceneX();
mouseOldY = me.getSceneY();
});
scene.setOnMouseDragged((MouseEvent me) -> {
mouseOldX = mousePosX;
mouseOldY = mousePosY;
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
mouseDeltaX = (mousePosX - mouseOldX);
mouseDeltaY = (mousePosY - mouseOldY);
if (me.isPrimaryButtonDown()) {
cameraXform.ry(mouseDeltaX * 180.0 / scene.getWidth());
cameraXform.rx(-mouseDeltaY * 180.0 / scene.getHeight());
} else if (me.isSecondaryButtonDown()) {
camera.setTranslateZ(camera.getTranslateZ() + mouseDeltaY);
}
});
}
public static void main(String[] args) {
launch(args);
}
}
class XformWorld extends Group {
final Translate t = new Translate(0.0, 0.0, 0.0);
final Rotate rx = new Rotate(0, 0, 0, 0, Rotate.X_AXIS);
final Rotate ry = new Rotate(0, 0, 0, 0, Rotate.Y_AXIS);
final Rotate rz = new Rotate(0, 0, 0, 0, Rotate.Z_AXIS);
public XformWorld() {
super();
this.getTransforms().addAll(t, rx, ry, rz);
}
}
class XformCamera extends Group {
Point3D px = new Point3D(1.0, 0.0, 0.0);
Point3D py = new Point3D(0.0, 1.0, 0.0);
Rotate r;
Transform t = new Rotate();
public XformCamera() {
super();
}
public void rx(double angle) {
r = new Rotate(angle, px);
this.t = t.createConcatenation(r);
this.getTransforms().clear();
this.getTransforms().addAll(t);
}
public void ry(double angle) {
r = new Rotate(angle, py);
this.t = t.createConcatenation(r);
this.getTransforms().clear();
this.getTransforms().addAll(t);
}
}
来源：https://stackoverflow.com/questions/31382634/javafx-3d-rotations