| jobData | 包含粒子属性。 |
实现此方法可访问和修改粒子属性。
You can use the following script to attract particles to a supplied position.
using System; using Unity.Collections; using UnityEngine; using UnityEngine.ParticleSystemJobs;
public class ParticleJob : MonoBehaviour { public float effectRange = 2.0f; public float effectStrength = 1.0f; public float oscillationSpeed = 12.0f; public bool useJobSystem = false;
private float oscillationPhase;
private ParticleSystem ps; private UpdateParticlesJob job = new UpdateParticlesJob(); private ParticleSystem.Particle[] mainThreadParticles;
private static float Remap(float x, float x1, float x2, float y1, float y2) { var m = (y2 - y1) / (x2 - x1); var c = y1 - m * x1;
return m * x + c; }
private static Vector3 CalculateVelocity(ref UpdateParticlesJob job, Vector3 delta) { float attraction = job.effectStrength / job.effectRangeSqr; return delta.normalized * attraction; }
private static Color32 CalculateColor(ref UpdateParticlesJob job, Vector3 delta, Color32 srcColor, UInt32 seed) { var targetColor = new Color32((byte)(seed >> 24), (byte)(seed >> 16), (byte)(seed >> 8), srcColor.a); float lerpAmount = delta.magnitude * job.inverseEffectRange; lerpAmount = lerpAmount * 0.25f + 0.75f; return Color32.Lerp(targetColor, srcColor, lerpAmount); }
void Start() { ps = GetComponent<ParticleSystem>(); oscillationPhase = UnityEngine.Random.Range(0.0f, Mathf.PI * 2.0f); }
void Update() { Vector2 mouse = Input.mousePosition; job.effectPosition = Camera.main.ScreenToWorldPoint(new Vector3(mouse.x, mouse.y, -Camera.main.transform.position.z)); job.effectRangeSqr = effectRange * effectRange; job.effectStrength = effectStrength * Remap(Mathf.Sin(oscillationPhase + Time.time * oscillationSpeed), -1, 1, -1, 0.5f); job.inverseEffectRange = (1.0f / effectRange);
if (!useJobSystem) { if (mainThreadParticles == null) mainThreadParticles = new ParticleSystem.Particle[ps.main.maxParticles];
var count = ps.GetParticles(mainThreadParticles); for (int i = 0; i < count; i++) { Vector3 position = mainThreadParticles[i].position; Vector3 delta = position - job.effectPosition; if (delta.sqrMagnitude < job.effectRangeSqr) { mainThreadParticles[i].velocity += CalculateVelocity(ref job, delta); mainThreadParticles[i].startColor = CalculateColor(ref job, delta, mainThreadParticles[i].startColor, mainThreadParticles[i].randomSeed); } } ps.SetParticles(mainThreadParticles, count); } }
void OnParticleUpdateJobScheduled() { if (useJobSystem) job.Schedule(ps); }
struct UpdateParticlesJob : IJobParticleSystem { [ReadOnly] public Vector3 effectPosition;
[ReadOnly] public float effectRangeSqr;
[ReadOnly] public float effectStrength;
[ReadOnly] public float inverseEffectRange;
public void Execute(ParticleSystemJobData particles) { var positionsX = particles.positions.x; var positionsY = particles.positions.y; var positionsZ = particles.positions.z;
var velocitiesX = particles.velocities.x; var velocitiesY = particles.velocities.y; var velocitiesZ = particles.velocities.z;
var colors = particles.startColors;
var randomSeeds = particles.randomSeeds;
for (int i = 0; i < particles.count; i++) { Vector3 position = new Vector3(positionsX[i], positionsY[i], positionsZ[i]); Vector3 delta = (position - effectPosition); if (delta.sqrMagnitude < effectRangeSqr) { Vector3 velocity = CalculateVelocity(ref this, delta);
velocitiesX[i] += velocity.x; velocitiesY[i] += velocity.y; velocitiesZ[i] += velocity.z;
colors[i] = CalculateColor(ref this, delta, colors[i], randomSeeds[i]); } } } } }
You can use the following script with the above example to supply the mouse position as the point to attract particles towards.
using UnityEditor; using UnityEngine;
public class ParticleSpawner : MonoBehaviour { public ParticleSystem prefab; public int systemCount = 128; public int particleEmissionRatePerSystem = 400; public float particleSystemShapeRadius = 1.0f; public float totalRadius = 5.0f; public float effectRange = 3.0f; public float effectStrength = 1.0f; public float oscillationSpeed = 10.0f; public bool hasTrails = true; public bool useJobSystem = false;
void Start() { var material = new Material(Shader.Find("Legacy Shaders/Particles/Additive")); material.SetTexture("_MainTex", AssetDatabase.GetBuiltinExtraResource<Texture2D>("Default-Particle.psd"));
for (int i = 0; i < systemCount; i++) { var go = GameObject.Instantiate(prefab); var ps = go.GetComponent<ParticleSystem>();
go.GetComponent<ParticleSystemRenderer>().sharedMaterial = material;
float x = (float)i / systemCount; float theta = x * Mathf.PI * 2;
var transform = go.GetComponent<Transform>(); transform.position = new Vector3(Mathf.Sin(theta), Mathf.Cos(theta), 0.0f) * totalRadius;
var main = ps.main; main.startColor = Color.HSVToRGB(x, Random.Range(0.5f, 1.0f), Random.Range(0.5f, 1.0f));
var emission = ps.emission; emission.rateOverTime = particleEmissionRatePerSystem;
var shape = ps.shape; shape.radius = particleSystemShapeRadius;
var trails = ps.trails; trails.enabled = hasTrails;
var updateJob = go.GetComponent<ParticleJob>(); updateJob.effectRange = effectRange; updateJob.effectStrength = effectStrength; updateJob.oscillationSpeed = oscillationSpeed; updateJob.useJobSystem = useJobSystem; } }
// UI void OnGUI() { float x = 25.0f; float y = 60.0f; float spacing = 40.0f;
EditorGUI.BeginChangeCheck();
GUIStyle backgroundStyle = new GUIStyle(GUI.skin.box); backgroundStyle.normal.background = Texture2D.whiteTexture; var oldColor = GUI.backgroundColor; GUI.backgroundColor = new Color(0.5f, 0.5f, 0.5f, 0.5f); GUI.Box(new Rect(x - 10, y - 35, 260, 230), "Options", backgroundStyle); GUI.backgroundColor = oldColor;
GUI.Label(new Rect(x, y, 140, 30), "Effect Range"); effectRange = GUI.HorizontalSlider(new Rect(x + 140, y + 5, 100, 30), effectRange, 0.0f, 10.0f); y += spacing;
GUI.Label(new Rect(x, y, 140, 30), "Effect Strength"); effectStrength = GUI.HorizontalSlider(new Rect(x + 140, y + 5, 100, 30), effectStrength, 0.0f, 10.0f); y += spacing;
GUI.Label(new Rect(x, y, 140, 30), "Oscillation Speed"); oscillationSpeed = GUI.HorizontalSlider(new Rect(x + 140, y + 5, 100, 30), oscillationSpeed, 0.0f, 20.0f); y += spacing;
hasTrails = GUI.Toggle(new Rect(x, y + 5, 140, 30), hasTrails, "Trails"); y += spacing;
useJobSystem = GUI.Toggle(new Rect(x, y + 5, 140, 30), useJobSystem, "Use C# Job System"); y += spacing;
if (EditorGUI.EndChangeCheck()) { ParticleJob[] updateJobs = GameObject.FindObjectsOfType<ParticleJob>(); for (int i = 0; i < updateJobs.Length; i++) { var updateJob = updateJobs[i]; updateJob.effectRange = effectRange; updateJob.effectStrength = effectStrength; updateJob.oscillationSpeed = oscillationSpeed; updateJob.useJobSystem = useJobSystem;
var ps = updateJob.GetComponent<ParticleSystem>();
var trails = ps.trails; trails.enabled = hasTrails; } } } }