JavaFX的移动鼠标3D对象的虚拟平面 [英] JavaFX Moving 3D objects with mouse on a virtual plane
问题描述
当我创建我的第一个3D游戏的JavaFX - 在那里你会能够从部分使用鼠标组装船只。这presents一个问题，因为JavaFX的好像还没有，对于转换PerspectiveCamera屏幕二维坐标到场景的三维空间工作的本地metods。
As I was creating my first 3D game in JavaFX - where you would be able to assemble ships from parts using the mouse. This presents a problem since JAVAFX seems to have no native metods that work for converting PerspectiveCamera screen 2D coordinates into the scene's 3D space.
下面是我想要获得了这幅重新presentation。使用鼠标移动块应该继续前进，就是始终相对于相机旋转90的假想平面：
Here is a representation of what I'm trying to acheive. A block moved by the mouse should move on an imaginary plane that is always rotated 90 in relation to the camera: I've tried to solve the problem with trigonometry without much success. I've not attached a code snippet as I'm looking for a more generic mathematical solution, but will provide it if requested.
所有帮助将是AP preciated！
All help would be appreciated!
期望的结果：
Desired result:
推荐答案
作为@ jdub1581指出，摄像机是鼠标移动绑定您的3D自用物品的关键现场。
As @jdub1581 points out, the Camera is the key to bind mouse movement with your 3D objets on the scene.
有关starterts，我们知道公共API PickResult ，使我们能够用鼠标选择基于某些光线追踪从摄像机位置进行技术的3D对象。
For starterts, we know about public API PickResult, that allows us to select a 3D object with the mouse, based on some ray tracing techniques performed from the camera position.
但是，一旦我们有一个对象，移动它是一个不同的问题。
But once we have an object, moving it is a different problem.
寻找这个问题（移动3D对象在3D空间中的2D鼠标）的解决方案前一段时间，我发现<一href="http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/5d371a34ddf1/apps/toys/FX8-3DFeatures/src/fx83dfeatures/Camera3D.java"相对=nofollow>在上的OpenJFX库中的精品项目Camera3D 类。
Looking for a solution for this problem (moving 3D objects with a 2D mouse in 3D space) a while ago, I found the Camera3D class at the Toys project on the OpenJFX repository.
它有一个叫做promissing方法 unProjectDirection ：
It has a promissing method called unProjectDirection:
/*
* returns 3D direction from the Camera position to the mouse
* in the Scene space
*/
public Vec3d unProjectDirection(double sceneX, double sceneY,
double sWidth, double sHeight) {
}
既然你问的数学解释，此方法使用您要找的三角。这将根据（X，Y）鼠标坐标给你一个3D矢量，使用专用 Vec3d 类（我们能与公众三维点<更换/ code>）：
Since you asked for mathematical explanation, this method uses the trigonometry you were looking for. This will give you a 3D vector based on (x,y) mouse coordinates, using a private Vec3d class (that we can replace with public Point3D):
double tanOfHalfFOV = Math.tan(Math.toRadians(camera.getFieldOfView()) * 0.5f);
Vec3d vMouse = new Vec3d(tanOfHalfFOV*(2*sceneX/sWidth-1), tanOfHalfFOV*(2*sceneY/sWidth-sHeight/sWidth), 1);
应用一些进一步的转换，以获得归一化矢量场景的坐标。
Some further transformations are applied to get a normalized vector in scene coordinates.
下一步将改变这个归一化向量的实际坐标，只是用从相机到物体的距离，上挑的结果给出，改造对象的位置。
The next step will transform this normalized vector in real coordinates, just using the distance from the camera to the object, given on the pick result, and transforming the object position.
基本上，这个片断code概述拖动对象的全过程：
Basically, this snippet of code outlines the whole process of dragging an object:
scene.setOnMousePressed((MouseEvent me) -> {
vecIni = unProjectDirection(me.getSceneX(), me.getSceneY(),
scene.getWidth(),scene.getHeight());
distance=me.getPickResult().getIntersectedDistance();
});
scene.setOnMouseDragged((MouseEvent me) -> {
vecPos = unProjectDirection(mousePosX, mousePosY,
scene.getWidth(),scene.getHeight());
Point3D p=vecPos.subtract(vecIni).multiply(distance);
node.getTransforms().add(new Translate(p.getX(),p.getY(),p.getZ()));
vecIni=vecPos;
distance=me.getPickResult().getIntersectedDistance();
});
这是一个完整的工作基本的例子：
And this is a full working basic example:
public class Drag3DObject extends Application {
private final Group root = new Group();
private PerspectiveCamera camera;
private final double sceneWidth = 800;
private final double sceneHeight = 600;
private double mousePosX;
private double mousePosY;
private double mouseOldX;
private double mouseOldY;
private final Rotate rotateX = new Rotate(-20, Rotate.X_AXIS);
private final Rotate rotateY = new Rotate(-20, Rotate.Y_AXIS);
private volatile boolean isPicking=false;
private Point3D vecIni, vecPos;
private double distance;
private Sphere s;
@Override
public void start(Stage stage) {
Box floor = new Box(1500, 10, 1500);
floor.setMaterial(new PhongMaterial(Color.GRAY));
floor.setTranslateY(150);
root.getChildren().add(floor);
Sphere sphere = new Sphere(150);
sphere.setMaterial(new PhongMaterial(Color.RED));
sphere.setTranslateY(-5);
root.getChildren().add(sphere);
Scene scene = new Scene(root, sceneWidth, sceneHeight, true, SceneAntialiasing.BALANCED);
scene.setFill(Color.web("3d3d3d"));
camera = new PerspectiveCamera(true);
camera.setVerticalFieldOfView(false);
camera.setNearClip(0.1);
camera.setFarClip(100000.0);
camera.getTransforms().addAll (rotateX, rotateY, new Translate(0, 0, -3000));
PointLight light = new PointLight(Color.GAINSBORO);
root.getChildren().add(light);
root.getChildren().add(new AmbientLight(Color.WHITE));
scene.setCamera(camera);
scene.setOnMousePressed((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
PickResult pr = me.getPickResult();
if(pr!=null && pr.getIntersectedNode() != null && pr.getIntersectedNode() instanceof Sphere){
distance=pr.getIntersectedDistance();
s = (Sphere) pr.getIntersectedNode();
isPicking=true;
vecIni = unProjectDirection(mousePosX, mousePosY, scene.getWidth(),scene.getHeight());
}
});
scene.setOnMouseDragged((MouseEvent me) -> {
mousePosX = me.getSceneX();
mousePosY = me.getSceneY();
if(isPicking){
vecPos = unProjectDirection(mousePosX, mousePosY, scene.getWidth(),scene.getHeight());
Point3D p=vecPos.subtract(vecIni).multiply(distance);
s.getTransforms().add(new Translate(p.getX(),p.getY(),p.getZ()));
vecIni=vecPos;
PickResult pr = me.getPickResult();
if(pr!=null && pr.getIntersectedNode() != null && pr.getIntersectedNode()==s){
distance=pr.getIntersectedDistance();
} else {
isPicking=false;
}
} else {
rotateX.setAngle(rotateX.getAngle()-(mousePosY - mouseOldY));
rotateY.setAngle(rotateY.getAngle()+(mousePosX - mouseOldX));
mouseOldX = mousePosX;
mouseOldY = mousePosY;
}
});
scene.setOnMouseReleased((MouseEvent me)->{
if(isPicking){
isPicking=false;
}
});
stage.setTitle("3D Dragging");
stage.setScene(scene);
stage.show();
}
/*
From fx83dfeatures.Camera3D
http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/5d371a34ddf1/apps/toys/FX8-3DFeatures/src/fx83dfeatures/Camera3D.java
*/
public Point3D unProjectDirection(double sceneX, double sceneY, double sWidth, double sHeight) {
double tanHFov = Math.tan(Math.toRadians(camera.getFieldOfView()) * 0.5f);
Point3D vMouse = new Point3D(tanHFov*(2*sceneX/sWidth-1), tanHFov*(2*sceneY/sWidth-sHeight/sWidth), 1);
Point3D result = localToSceneDirection(vMouse);
return result.normalize();
}
public Point3D localToScene(Point3D pt) {
Point3D res = camera.localToParentTransformProperty().get().transform(pt);
if (camera.getParent() != null) {
res = camera.getParent().localToSceneTransformProperty().get().transform(res);
}
return res;
}
public Point3D localToSceneDirection(Point3D dir) {
Point3D res = localToScene(dir);
return res.subtract(localToScene(new Point3D(0, 0, 0)));
}
public static void main(String[] args) {
launch(args);
}
}
这将允许您挑选和拖拽球体上的情景：
That will allow you picking and dragging the sphere on the scene:
这篇关于JavaFX的移动鼠标3D对象的虚拟平面的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
