Question

我正试图在所有物体之间实施引力。所有尝试实现类似的东西都会导致对象的奇怪行为。这是我实现的代码的一个版本。它不起作用：

public void updateGravitation() {

    for (GravitationalBody aGravitationalBody : gravitationalBodies){
        double sumX = 0;
        double sumY = 0;
        for (GravitationalBody bGravitationalBody : gravitationalBodies){
            if (aGravitationalBody != bGravitationalBody) {

                double massMultiplication = aGravitationalBody.getMass() * bGravitationalBody.getMass();

                double distanceX = aGravitationalBody.getPosition().x - bGravitationalBody.getPosition().x;
                double distanceY = aGravitationalBody.getPosition().y - bGravitationalBody.getPosition().y;

                double r = Math.sqrt(Math.pow(distanceX,2) + Math.pow(distanceY,2));

                double force = G * massMultiplication/(r * r);

                double theta = distanceY / distanceX;

                sumX += force * theta;
                sumY += force * theta;

            }
        }
        aGravitationalBody.appleForce(sumX,sumY);
    }
}

我做错了什么？

PS新年快乐！
PSS抱歉英语不好。

Answer 1

难道你不觉得力的X-Y分量始终相等吗？再想一想distanceY / distanceX

谢谢Margaret Bloom。我将代码更改为：

public void updateGravitation() {

    for (GravitationalBody aGravitationalBody : gravitationalBodies){
        double sumX = 0;
        double sumY = 0;
        for (GravitationalBody bGravitationalBody : gravitationalBodies){
            if (aGravitationalBody != bGravitationalBody) {

                double massMultiplication = aGravitationalBody.getMass() * bGravitationalBody.getMass();

                double distanceX = aGravitationalBody.getPosition().x - bGravitationalBody.getPosition().x;
                double distanceY = aGravitationalBody.getPosition().y - bGravitationalBody.getPosition().y;

                double r = Math.sqrt(Math.pow(distanceX,2) + Math.pow(distanceY,2));

                double force = G * massMultiplication/(r * r);

                sumX += -1*force * distanceX/r;
                sumY += -1*force * distanceY/r;

            }
        }
        aGravitationalBody.appleForce(sumX,sumY);
    }
}

现在工作正常

所有物体之间的引力。 Java的

1 个答案: