public void applyRepel(KParticle other, float timeElapsed)
{
var dis = (other.transform.position - transform.position).XY() + new Vector2(.001f, .001f);
float disMag = dis.magnitude;
if (disMag > disIdeal) return;
Vector2 dir;
if (disMag != 0) dir = new Vector2(dis.x / disMag, dis.y / disMag);
else
{
float angleRan = Random.Range(0, 3.14f * 2);
dir = new Vector2(Mathf.Cos(angleRan), Mathf.Sin(angleRan));
}
float ratio = 1 - disMag / disIdeal;
float factor = ratio * (pressureRatio + pressureNearRatio * ratio) / (2 * disMag);
Vector2 d = dis * factor;
Vector2 veloDiff = other.rigidbody2D.velocity - rigidbody2D.velocity;
factor = VISCOSITY * ratio * DT;
d -= veloDiff * factor * timeElapsed;
//Debug.Log(d);
applyForce(d * -1.0f);
other.applyForce(d);
}
void applyPressure_5_01(KParticle other, int index, float timeElapsed = .001f)
{
if (arrayDis[index] > disIdeal) return;
var dis = (other.transform.position - transform.position).XY() + new Vector2(.001f, .001f);
float disMag = arrayDis[index];
Vector2 dir = (arrayDis[index] > .01f) ?
new Vector2(dis.x / disMag, dis.y / disMag) :
helperRandomDir();
float ratio = 1.0f - disMag / disIdeal;
float factor = ratio * (pressureRatio + pressureNearRatio * ratio) / (2 * disMag); // / (2 * disMag);
Vector2 d = dis * factor;
Vector2 veloDiff = other.rigidbody2D.velocity - rigidbody2D.velocity;
d -= veloDiff * factor * timeElapsed;
//Debug.Log(pressureRatio + " " + pressureNearRatio + " " + ratio + " = " + factor);
d = dir * factor;
var vChange = (other.rigidbody2D.velocity - rigidbody2D.velocity) * ratio;
//Debug.Log(d);
applyForce(d * -1.0f + vChange);
other.applyForce(d - vChange);
}