public bool IsColliding(SoftBodyParticleData other)
{
Vector3 s = position - other.position; // vector between the centers of each sphere
Vector3 v = velocity - other.velocity; // relative velocity between spheres
float r = size + other.size;
float t = 0;
float c = Vector3.Dot(s, s) - r * r; // if negative, they overlap
if (c < 0.0f) // if true, they already overlap
{
t = .0f;
return(true);
}
float a = Vector3.Dot(v, v);
float b = Vector3.Dot(v, s);
if (b >= 0.0f)
{
return(false); // does not move towards each other
}
float d = b * b - a * c;
if (d < 0.0f)
{
return(false); // no real roots ... no collision
}
t = (-b - Mathf.Sqrt(d)) / a;
return(true);
}
private void Start()
{
int size = 128;
particlesData = new NativeArray <SoftBodyParticleData>(size, Allocator.Persistent);
for (int i = 0; i < size; i++)
{
var d = new SoftBodyParticleData();
d.size = Random.Range(.5f, 1f);
d.mass = d.size * 5;
d.position = new Vector3(0, 5, 0) + new Vector3(0, i, 0);
particlesData[i] = d;
}
particles = new ParticleSystem.Particle[particlesData.Length];
particlesNative = new NativeArray <ParticleSystem.Particle>(particles, Allocator.Persistent);
}
public void Resolve(SoftBodyParticleData coll)
{
float m1, m2, x1, x2;
var x = (position - coll.position).normalized;
Vector3 v1, v2, v1x, v2x, v1y, v2y;
v1 = velocity;
x1 = Vector3.Dot(x, v1);
v1x = x * x1;
v1y = v1 - v1x;
m1 = mass;
x = x * -1;
v2 = coll.velocity;
x2 = Vector3.Dot(x, v2);
v2x = x * x2;
v2y = v2 - v2x;
m2 = coll.mass;
velocity = v1x * (m1 - m2) / (m1 + m2) + v2x * (2 * m2) / (m1 + m2) + v1y;
coll.velocity = v1x * (2 * m1) / (m1 + m2) + v2x * (m2 - m1) / (m1 + m2) + v2y;
}