| streams | Streams to enable. | 
Enable a set of vertex shader streams on the Particle System renderer.
See Also: ParticleSystemRenderer.DisableVertexStreams, ParticleSystem.SetCustomParticleData.
using UnityEngine; using UnityEditor; using System.Collections.Generic;
public class ExampleClass : MonoBehaviour {
private ParticleSystem ps; private ParticleSystemRenderer psr; private List<Vector4> customData = new List<Vector4>(); public float minDist = 30.0f;
void Start() {
ps = GetComponent<ParticleSystem>(); psr = GetComponent<ParticleSystemRenderer>();
// emit in a sphere with no speed var main = ps.main; main.startSpeedMultiplier = 0.0f; main.simulationSpace = ParticleSystemSimulationSpace.World; // so our particle positions don't require any extra transformation, to compare with the mouse position var emission = ps.emission; emission.rateOverTimeMultiplier = 200.0f; var shape = ps.shape; shape.shapeType = ParticleSystemShapeType.Sphere; shape.radius = 4.0f; psr.sortMode = ParticleSystemSortMode.YoungestInFront;
// send custom data to the shader psr.EnableVertexStreams(ParticleSystemVertexStreams.Custom1); }
void Update() {
Camera mainCam = Camera.main;
ps.GetCustomParticleData(customData, ParticleSystemCustomData.Custom1);
int particleCount = ps.particleCount; ParticleSystem.Particle[] particles = new ParticleSystem.Particle[particleCount]; ps.GetParticles(particles);
for (int i = 0; i < particles.Length; i++) { Vector3 sPos = mainCam.WorldToScreenPoint(particles[i].position + ps.transform.position);
// set custom data to 1, if close enough to the mouse if (Vector2.Distance(sPos, Input.mousePosition) < minDist) { customData[i] = new Vector4(1, 0, 0, 0); } // otherwise, fade the custom data back to 0 else { float particleLife = particles[i].remainingLifetime / ps.main.startLifetimeMultiplier;
if (customData[i].x > 0) { float x = customData[i].x; x = Mathf.Max(x - Time.deltaTime, 0.0f); customData[i] = new Vector4(x, 0, 0, 0); } } }
ps.SetCustomParticleData(customData, ParticleSystemCustomData.Custom1); }
void OnGUI() {
minDist = GUI.HorizontalSlider(new Rect(25, 40, 100, 30), minDist, 0.0f, 100.0f); } }
Here is an example of a custom shader that can be used with the above script:
          Shader "Particles/CustomVertexStream" {
Properties {
    _TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
    _MainTex ("Particle Texture", 2D) = "white" {}
    _OffsetValue("Offset Value", Range(0,1)) = 0.4
}
Category {
    Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }
    Blend SrcAlpha OneMinusSrcAlpha
    ColorMask RGB
    Cull Off Lighting Off ZWrite Off
    SubShader {
        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_particles
            #pragma multi_compile_fog
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            fixed4 _TintColor;
            float _OffsetValue;
            struct appdata_t {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                fixed4 color : COLOR;
                float2 texcoord : TEXCOORD0;
                float4 customData : TEXCOORD1;
            };
            struct v2f {
                float4 vertex : SV_POSITION;
                fixed4 color : COLOR;
                float2 texcoord : TEXCOORD0;
                float4 customData : TEXCOORD1;
                UNITY_FOG_COORDS(2)
            };
            float4 _MainTex_ST;
            v2f vert (appdata_t v)
            {
                v.vertex.y = lerp(v.vertex.y, v.vertex.y + _OffsetValue, v.customData.x);
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                float4 offsetX = float4(-1, 1, 1, -1);
                float4 offsetY = float4(1, 1, -1, -1);
                o.color = v.color;
                o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
                o.customData = v.customData;
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }
            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
                fixed4 col2 = fixed4(i.customData.x, i.customData.y, i.customData.z, col.a);
                fixed4 final = lerp(col, col*col2, i.customData.x);
                UNITY_APPLY_FOG(i.fogCoord, final);
                return final;
            }
            ENDCG
        }
    }
}
}