| particles | 输出粒子缓冲区，其中包含当前粒子状态。 |
| size | The number of elements that are read from the Particle System. |
| offset | The offset into the active particle list, from which to copy the particles. |
int 写入输入粒子数组的粒子数（当前存活的粒子数）。
Gets the particles of this Particle System.
This method is allocation free as long the input "particles" array is preallocated once (see example below). The method only gets the particles that are currently alive in the Particle System when it is called, so it may only get a small part of the particles array.
另请参阅：Particle、SetParticles。
using UnityEngine;
[RequireComponent(typeof(ParticleSystem))] public class ParticleFlow : MonoBehaviour { ParticleSystem m_System; ParticleSystem.Particle[] m_Particles; public float m_Drift = 0.01f;
private void LateUpdate() { InitializeIfNeeded();
// GetParticles is allocation free because we reuse the m_Particles buffer between updates int numParticlesAlive = m_System.GetParticles(m_Particles);
// Change only the particles that are alive for (int i = 0; i < numParticlesAlive; i++) { m_Particles[i].velocity += Vector3.up * m_Drift; }
// Apply the particle changes to the Particle System m_System.SetParticles(m_Particles, numParticlesAlive); }
void InitializeIfNeeded() { if (m_System == null) m_System = GetComponent<ParticleSystem>();
if (m_Particles == null || m_Particles.Length < m_System.main.maxParticles) m_Particles = new ParticleSystem.Particle[m_System.main.maxParticles]; } }