ParticleSystem.simulationSpace

Description

This selects the space in which to simulate particles. It can be either world or local space.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public ParticleSystem part;
    public bool useLocal = true;
    void Start() {
        part = GetComponent<ParticleSystem>();
        useLocal = part.simulationSpace == ParticleSystemSimulationSpace.Local;
    }
    void Update() {
        part.simulationSpace = ((useLocal) ? ParticleSystemSimulationSpace.Local : ParticleSystemSimulationSpace.World);
    }
    void OnGUI() {
        useLocal = GUI.Toggle(new Rect(10, 60, 200, 30), useLocal, " Use Local Simulation Space");
    }
}