C# 二维球之间的吸引力
我有一个模拟,多个圆在2D空间中移动,它们之间有弹性碰撞 我想在粒子之间加一个引力,这样粒子就可以根据质量向其他粒子移动,等等。我该怎么做呢 我的冲突管理功能如下所示:C# 二维球之间的吸引力,c#,gravity,C#,Gravity,我有一个模拟,多个圆在2D空间中移动,它们之间有弹性碰撞 我想在粒子之间加一个引力,这样粒子就可以根据质量向其他粒子移动,等等。我该怎么做呢 我的冲突管理功能如下所示: void manageCollision(Particle particleA, Particle particleB) { float distanceX = particleA.Position.X - particleB.Position.X; float distanceY = particleA.Pos
void manageCollision(Particle particleA, Particle particleB)
{
float distanceX = particleA.Position.X - particleB.Position.X;
float distanceY = particleA.Position.Y - particleB.Position.Y;
double collisionAngle = Math.Atan2(distanceY, distanceX);
double pA_magnitude = Math.Sqrt(particleA.Velocity.X * particleA.Velocity.X + particleA.Velocity.Y * particleA.Velocity.Y);
double pB_magnitude = Math.Sqrt(particleB.Velocity.X * particleB.Velocity.X + particleB.Velocity.Y * particleB.Velocity.Y);
double pA_direction = Math.Atan2(particleA.Velocity.Y, particleA.Velocity.X);
double pB_direction = Math.Atan2(particleB.Velocity.Y, particleB.Velocity.X);
double pA_newVelocityX = pA_magnitude * Math.Cos(pA_direction - collisionAngle);
double pA_newVelocityY = pA_magnitude * Math.Sin(pA_direction - collisionAngle);
double pB_newVelocityX = pB_magnitude * Math.Cos(pB_direction - collisionAngle);
double pB_newVelocityY = pB_magnitude * Math.Sin(pB_direction - collisionAngle);
double pA_finalVelocityX = ((particleA.Mass - particleB.Mass) * pA_newVelocityX + (particleB.Mass + particleB.Mass) * pB_newVelocityX) / (particleA.Mass + particleB.Mass);
double pB_finalVelocityX = ((particleA.Mass + particleA.Mass) * pA_newVelocityX + (particleB.Mass - particleA.Mass) * pB_newVelocityX) / (particleA.Mass + particleB.Mass);
double pA_finalVelocityY = pA_newVelocityY;
double pB_finalVelocityY = pB_newVelocityY;
particleA.Velocity = new Vector2((float)(Math.Cos(collisionAngle) * pA_finalVelocityX + Math.Cos(collisionAngle + Math.PI / 2) * pA_finalVelocityY), (float)(Math.Sin(collisionAngle) * pA_finalVelocityX + Math.Sin(collisionAngle + Math.PI / 2) * pA_finalVelocityY));
particleB.Velocity = new Vector2((float)(Math.Cos(collisionAngle) * pB_finalVelocityX + Math.Cos(collisionAngle + Math.PI / 2) * pB_finalVelocityY), (float)(Math.Sin(collisionAngle) * pB_finalVelocityX + Math.Sin(collisionAngle + Math.PI / 2) * pB_finalVelocityY));
}
Vector2 globalGravity = new Vector2(0f, gravityScale / 6000);
for (int i = 0; i < particles.Count(); i++)
{
particles[i].Update((float)updateTimer.Interval, globalGravity);
Vector2 position = particles[i].Position;
Vector2 velocity = particles[i].Velocity;
collisionWallCheck(ref position, ref velocity, particles[i].Radius);
particles[i].Position = position;
particles[i].Velocity = velocity;
Particle pA = particles[i];
for (int k = i + 1; k < particles.Count(); k++)
{
Particle pB = particles[k];
Vector2 delta = pA.Position - pB.Position;
float dist = delta.Length();
if (dist < particles[i].Radius + particles[k].Radius && !particles[i].Colliding && !particles[k].Colliding)
{
particles[i].Colliding = true;
particles[k].Colliding = true;
manageCollision(particles[i], particles[k]);
particles[i].initColorTable(); // Upon collision, change the color
particles[k].initColorTable();
totalCollisions++;
}
else
{
particles[i].Colliding = false;
particles[k].Colliding = false;
}
}
}
每个球或粒子以随机质量和半径繁殖
函数在更新类型的方法中调用,如下所示:
void manageCollision(Particle particleA, Particle particleB)
{
float distanceX = particleA.Position.X - particleB.Position.X;
float distanceY = particleA.Position.Y - particleB.Position.Y;
double collisionAngle = Math.Atan2(distanceY, distanceX);
double pA_magnitude = Math.Sqrt(particleA.Velocity.X * particleA.Velocity.X + particleA.Velocity.Y * particleA.Velocity.Y);
double pB_magnitude = Math.Sqrt(particleB.Velocity.X * particleB.Velocity.X + particleB.Velocity.Y * particleB.Velocity.Y);
double pA_direction = Math.Atan2(particleA.Velocity.Y, particleA.Velocity.X);
double pB_direction = Math.Atan2(particleB.Velocity.Y, particleB.Velocity.X);
double pA_newVelocityX = pA_magnitude * Math.Cos(pA_direction - collisionAngle);
double pA_newVelocityY = pA_magnitude * Math.Sin(pA_direction - collisionAngle);
double pB_newVelocityX = pB_magnitude * Math.Cos(pB_direction - collisionAngle);
double pB_newVelocityY = pB_magnitude * Math.Sin(pB_direction - collisionAngle);
double pA_finalVelocityX = ((particleA.Mass - particleB.Mass) * pA_newVelocityX + (particleB.Mass + particleB.Mass) * pB_newVelocityX) / (particleA.Mass + particleB.Mass);
double pB_finalVelocityX = ((particleA.Mass + particleA.Mass) * pA_newVelocityX + (particleB.Mass - particleA.Mass) * pB_newVelocityX) / (particleA.Mass + particleB.Mass);
double pA_finalVelocityY = pA_newVelocityY;
double pB_finalVelocityY = pB_newVelocityY;
particleA.Velocity = new Vector2((float)(Math.Cos(collisionAngle) * pA_finalVelocityX + Math.Cos(collisionAngle + Math.PI / 2) * pA_finalVelocityY), (float)(Math.Sin(collisionAngle) * pA_finalVelocityX + Math.Sin(collisionAngle + Math.PI / 2) * pA_finalVelocityY));
particleB.Velocity = new Vector2((float)(Math.Cos(collisionAngle) * pB_finalVelocityX + Math.Cos(collisionAngle + Math.PI / 2) * pB_finalVelocityY), (float)(Math.Sin(collisionAngle) * pB_finalVelocityX + Math.Sin(collisionAngle + Math.PI / 2) * pB_finalVelocityY));
}
Vector2 globalGravity = new Vector2(0f, gravityScale / 6000);
for (int i = 0; i < particles.Count(); i++)
{
particles[i].Update((float)updateTimer.Interval, globalGravity);
Vector2 position = particles[i].Position;
Vector2 velocity = particles[i].Velocity;
collisionWallCheck(ref position, ref velocity, particles[i].Radius);
particles[i].Position = position;
particles[i].Velocity = velocity;
Particle pA = particles[i];
for (int k = i + 1; k < particles.Count(); k++)
{
Particle pB = particles[k];
Vector2 delta = pA.Position - pB.Position;
float dist = delta.Length();
if (dist < particles[i].Radius + particles[k].Radius && !particles[i].Colliding && !particles[k].Colliding)
{
particles[i].Colliding = true;
particles[k].Colliding = true;
manageCollision(particles[i], particles[k]);
particles[i].initColorTable(); // Upon collision, change the color
particles[k].initColorTable();
totalCollisions++;
}
else
{
particles[i].Colliding = false;
particles[k].Colliding = false;
}
}
}
我现在不确定如何处理0的情况。知道所有球的位置和它们的质量,你可以计算出任何两个物体之间感受到的力的矢量。找到从球“A”到所有其他球的向量-“A”到球“B”,“A”到“C”,“A”到“D”等。然后,简单地将所有A的向量相加,得到作用在A上的力的最终向量。重复B->A,B->C等以找到B的向量。这样做,计算新的速度,并调整步骤之间的时间量的位置。了解所有球的位置及其质量,您可以计算任意两个物体之间的力矢量。找到从球“A”到所有其他球的向量-“A”到球“B”,“A”到“C”,“A”到“D”等。然后,简单地将所有A的向量相加,得到作用在A上的力的最终向量。重复B->A,B->C等以找到B的向量。对所有对象执行此操作,计算新的速度,并调整步骤之间的时间量的位置。首先计算作用在每个对象上的重力。这是由
F = Gm1m2/r*r
其中m1和m2是两个物体的质量,G是,r是两个物体之间的距离
现在,r是一个向量,所以你可能想把它分成单独的部分——Fx和Fy。您可以按如下方式执行此操作:
Fx = F * cos(theta)
Fy = F * sin(theta)
对于每个质量,计算作用于它和其他每个物体上的重力。得到重力的净力。(请注意,该链接符合您的兴趣,但需要很长时间才能切中要害)。在这一点上,每个物体上都有一个净力,从中可以计算加速度。以下是达到这一点的代码:
const double G = 6.67398 * 0.00000000001;
for (int i = 0; i < particles.Count(); i++)
{
double sumX = 0;
double sumY = 0;
for (int j = 0; j < particles.Count(); j++)
{
// Don't add attraction to self
if (i == j)
continue;
double distanceX = particles[i].Position.X - particles[j].Position.X;
double distanceY = particles[i].Position.Y - particles[j].Position.Y;
double r = Math.Sqrt(Math.Pow(distanceX, 2) + Math.Pow(distanceY, 2));
double force = G * particles[i].Mass * particles[j].Mass / (r * r);
double theta = Math.Tan(distanceY / distanceX);
sumX += force * Math.Cos(theta);
sumY += force * Math.Sin(theta);
}
double netForce = Math.Sqrt(Math.Pow(sumX, 2) + Math.Pow(sumY, 2));
double a = netForce / particles[i].Mass;
double aTheta = Math.Tan(sumY / sumX);
// Here we get accelerations for X and Y. You can probably figure out velocities from here.
double aX = a * Math.Cos(aTheta);
double aY = a * Math.Sin(aTheta);
}
constdouble G=6.67398*0.00000000001;
对于(int i=0;i
注释
这并没有考虑到0值之类的东西——您必须清理此代码以处理特殊情况,然后才能运行而不会崩溃
在计算所有力之前,不要更新任何位置,否则将禁用列表中的后续元素
另一件值得注意的事情是:这个算法是O(n^2),所以如果你有多个实体,它将需要大量的压缩。不幸的是,事情就是这样;如果你找到一种快速计算大量天体引力的方法,你可能应该打电话给NASA
根据您的坐标系,您可能会发现y向量正在反转。这是因为欧几里德几何学认为y的正值是“向上”的,而程序员倾向于从屏幕顶部“向下”以正单位测量y。这会破坏你的角度和物体。首先计算作用在每个物体上的重力。这是由
F = Gm1m2/r*r
其中m1和m2是两个物体的质量,G是,r是两个物体之间的距离
现在,r是一个向量,所以你可能想把它分成单独的部分——Fx和Fy。您可以按如下方式执行此操作:
Fx = F * cos(theta)
Fy = F * sin(theta)
对于每个质量,计算作用于它和其他每个物体上的重力。得到重力的净力。(请注意,该链接符合您的兴趣,但需要很长时间才能切中要害)。在这一点上,每个物体上都有一个净力,从中可以计算加速度。以下是达到这一点的代码:
const double G = 6.67398 * 0.00000000001;
for (int i = 0; i < particles.Count(); i++)
{
double sumX = 0;
double sumY = 0;
for (int j = 0; j < particles.Count(); j++)
{
// Don't add attraction to self
if (i == j)
continue;
double distanceX = particles[i].Position.X - particles[j].Position.X;
double distanceY = particles[i].Position.Y - particles[j].Position.Y;
double r = Math.Sqrt(Math.Pow(distanceX, 2) + Math.Pow(distanceY, 2));
double force = G * particles[i].Mass * particles[j].Mass / (r * r);
double theta = Math.Tan(distanceY / distanceX);
sumX += force * Math.Cos(theta);
sumY += force * Math.Sin(theta);
}
double netForce = Math.Sqrt(Math.Pow(sumX, 2) + Math.Pow(sumY, 2));
double a = netForce / particles[i].Mass;
double aTheta = Math.Tan(sumY / sumX);
// Here we get accelerations for X and Y. You can probably figure out velocities from here.
double aX = a * Math.Cos(aTheta);
double aY = a * Math.Sin(aTheta);
}
constdouble G=6.67398*0.00000000001;
对于(int i=0;i
注释
这不需要像0-va这样的东西