jBullet相机“保持架”不动

Question

我使用jBullet和OpenGL来创建一个基本的游戏引擎。我创建了两个类，名为ObjectSurface和ObjectEntity。基本上，ObjectSurface没有质量，所以它们不会移动，ObjectEntity可以通过碰撞或重力来移动。

我创建了一个带有ObjectEntity对象的照相机，名为cameraHolder，这样它就可以掉下来，并发生碰撞等等。

问题是，当按下特定的cameraHolder WASD键时，它应该移动，但它只移动一个单元，不再移动。当按钮被释放时，它会将一个单元移动到相反的方向，从而使您处于相同的位置。在cameraHolder移动之后，相机的XYZ被设置为cameraHolder的XYZ坐标。

然而，该运动适用于由于重力而下降的jBullet所引起的运动。

当我不使用jBullet更新时，cameraHolder就会正常移动。因此，问题应该是jBullet更新。我将在代码中展示这一点。

问题：为什么cameraHolder只移动一个单元，然后当按下特定的WASD按钮时返回？

下面是Camera.java类中运动的代码：

public void move(float amount, float direction) {

if(!still){
    if (direction == MOVE_BACKWARD) {
        //MOVE BACKWARDS (CODE NOT NEEDED, WORKS WITHOUT CAMERA CARRIER)
        }

        if (direction == MOVE_FORWARD) {
        //MOVE FORWARD
        }

        if (direction == MOVE_LEFT) {
        //MOVE LEFT
        }

        if (direction == MOVE_RIGHT) {
        //MOVE RIGHT
        }
    }
}

public void carryCamera() {
    if(!still){
    x = cameraHolder.pos.x;
    y = cameraHolder.pos.y;
    z = cameraHolder.pos.z;
    }
}

下面是如何创建ObjectEntity：

private void createShape() {
    DefaultMotionState fallMotionState = new DefaultMotionState(new Transform(new Matrix4f(new Quat4f(0, 0, 0, 1), new Vector3f(pos.x, pos.y, pos.z), 1.0f)));
    Vector3f fallInertia = new Vector3f(0,0,0); 
    shape.calculateLocalInertia(mass,fallInertia); 
    RigidBodyConstructionInfo fallRigidBodyCI = new RigidBodyConstructionInfo(mass,fallMotionState,shape,fallInertia); 
    body = new RigidBody(fallRigidBodyCI); 
    Engine.getDynamicsWorld().addRigidBody(body); 
}

以下是物理世界是如何创建的：

private static void initPhysics() {
    BroadphaseInterface broadphase = new DbvtBroadphase();
    DefaultCollisionConfiguration collisionConfiguration = new DefaultCollisionConfiguration();
    CollisionDispatcher dispatcher = new CollisionDispatcher(collisionConfiguration);
    SequentialImpulseConstraintSolver solver = new SequentialImpulseConstraintSolver();
    dynamicsWorld = new DiscreteDynamicsWorld(dispatcher, broadphase, solver, collisionConfiguration);
    dynamicsWorld.setGravity(Game.gravity);
}

如何获取输入和更新物理(本部分中有可疑代码)：

public static Vector3f gravity = new Vector3f(0, -10, 0); //GRAVITY
private ArrayList<Object> objects; //ALL THE OBJECTS IN THE GAME (CAMERAHOLDER IS IN HERE)

        //GETTING INPUT, USING move() METHOD IN CAMERA CLASS TO MOVE HOLDER.
public void getInput() {

    if (Keyboard.isKeyDown(Keyboard.KEY_LCONTROL))
        speedMultiplier = 3;

    if (Keyboard.isKeyDown(Keyboard.KEY_W))
        cam.move(cam.getMoveSpeed() * speedMultiplier, Camera.MOVE_FORWARD);

    if (Keyboard.isKeyDown(Keyboard.KEY_S))
        cam.move(cam.getMoveSpeed() * speedMultiplier, Camera.MOVE_BACKWARD);

    if (Keyboard.isKeyDown(Keyboard.KEY_A))
        cam.move(cam.getMoveSpeed() * speedMultiplier, Camera.MOVE_LEFT);

    if (Keyboard.isKeyDown(Keyboard.KEY_D))
        cam.move(cam.getMoveSpeed() * speedMultiplier, Camera.MOVE_RIGHT);

    cam.carryCamera(); //MOVES THE ACTUAL CAMERA TO THE HOLDER.
    speedMultiplier = 1;

}

public void update() {
    applyJBullet();
}

        //AND JBULLET PHYSICS ARE APPLIED HERE (SUSPICIOUS CODE!!!)
public void applyJBullet(){
Engine.getDynamicsWorld().stepSimulation(1/60.f, 10); //SIMULATES NEXT FRAME

    for (Object o : objects) { 
        if(o.getMass() >= 1){ //ALL THE OBJECTS WITH MASS ARE FOUND

    Transform trans = new Transform();   //CREATING A NEW TRANSFORM
    o.getBody().getMotionState().getWorldTransform(trans); //GET THE SIMULATED LOCATION

//It still doesn't work when I do: "trans.origin.x+=2" here. The same problem occurs.
    o.setPos(trans.origin); //AND SET IT AS THE OBJECTS POSITION
        }   
    }
}

Answer 1

我认为比仅仅使用盒子形状更好的原因是要有一个运动体。若要将相机机身转换为“运动体”(更好的单向碰撞，由用户移动)，请调用以下命令：

body.setCollisionFlags(body.ge­tCollisionFlags() | CollisionFlags.KINEMATIC_OBJEC­T);
body.setActivationState(Collis­ionObject.DISABLE_DEACTIVATION­);