# Cyclone particles

I’m trying to figure out how to do radial/tangential velocity with the new particle system (shuriken). There doesn’t seem to be any non-cartesian velocity system. How would I do something like a cyclone where particles have positive velocity in Y-axis but have constant tangential velocity?

I didn’t tried the Shuriken system yet, but with the old particle system (should work with Shuriken as well) you can manipulate the particles manually via script. I’ve created a planetary simulation (general gravity law ;)) and works well even with 5000+ particles (still 60fps). I pushed it to 14k particles and still have 30fps on my old 32Bit dual core.

``````// C#
public ParticleEmitter m_PE;

void FixedUpdate()
{
Vector3 center = transform.position;
Particle[] particles = m_PE.particles;
for (int i = 0; i < particles.Length;i++)
{
Particle P = particles*;*
``````

Vector3 g = center - P.position;
float distSqr = g.sqrMagnitude;
g /= Mathf.Sqrt(distSqr);
float a = Mass / distSqr;
P.velocity += gaTime.deltaTime;
P.position += P.velocity*Time.deltaTime;
particles = P;
}
m_PE.particles = particles;
}
You need to find your own interpolation since there is no radial velocity in physics without some kind of force that pulls towards a center.
Note: I don’t use the ParticlaAnimator component at all. I move the particles myself as you can see.