ParticleFire.shader

Shader "Particles/Fire"
{
    Properties
    {
        _MainTex("Texture", 2D) = "white" {}
        _Noise("Noise Texture", 2D) = "white" {}
        _Distort("Second Noise Texture", 2D) = "white" {}
        _Scale("Noise Scale", Range(0,2)) = 0.5
        _DistortScale("Distort Scale", Range(0,2)) = 0.5
        _Tint("Tint", Color) = (1,1,0,0) // Color of the dissolve Line
        _EdgeColor("Edge", Color) = (1,0.5,0,0) // Color of the dissolve Line)
        _Cutoff("Cutoff Smoothness", Range(0,1)) = 0.2
        _Speed("Speed", Range(-10,10)) = 2
        _Brightness("Brightness", Range(0,2)) = 0.6
        _Stretch("Stretch", Range(0,2)) = 1
        _EdgeWidth("EdgeWidth", Range(0,2)) = 0.4
        _Particle("Density", Range(-2,2)) = 0
        [Toggle(MULTIPLY)] _MULTIPLY("Multiply Noise?", Float) = 1

    }
        SubShader
        {
            Tags { "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" "PreviewType" = "Plane" }
        Blend One OneMinusSrcAlpha
        ColorMask RGB
         Lighting Off ZWrite Off

            Pass
            {
                CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                // make fog work
                #pragma multi_compile_fog
                #pragma shader_feature MULTIPLY

                #include "UnityCG.cginc"

                struct appdata
                {
                    float4 vertex : POSITION;
                    float3 uv : TEXCOORD0;// .z has particle age
                    float4 color : COLOR;
                    float4 normal :NORMAL;
                };

                struct v2f
                {
                    float3 uv : TEXCOORD0; // .z has particle age
                    UNITY_FOG_COORDS(1)
                    float4 vertex : SV_POSITION;
                    float4 color: COLOR;
                    float3 worldPos : TEXCOORD2;
                    float3 worldNormal : TEXCOORD3;

                };

                sampler2D _MainTex,_Noise, _Distort;
                float4 _MainTex_ST, _Noise_ST, _Tint, _EdgeColor;
                float _Scale, _DistortScale, _Cutoff, _Speed, _Brightness, _Stretch, _EdgeWidth, _Particle;
                v2f vert(appdata v)
                {
                    v2f o;
                    o.worldNormal = mul(unity_ObjectToWorld,v.normal);
                    o.vertex = UnityObjectToClipPos(v.vertex);
                    o.uv.xy = TRANSFORM_TEX(v.uv.xy, _MainTex);
                    o.worldPos = mul(unity_ObjectToWorld, v.vertex);
                    UNITY_TRANSFER_FOG(o,o.vertex);
                    o.uv.z = v.uv.z;
                    o.color = v.color;
                    return o;
                }

                fixed4 frag(v2f i) : SV_Target
                {
                    // sample the texture

                    float3 blendNormal = saturate(pow(i.worldNormal * 1.4,4));

                    float flowspeed = _Time.y * _Speed;

                    i.worldPos.y -= flowspeed;
                    i.worldPos.y *= _Stretch;

                    // normal distort triplanar for x, y, z sides
                    float3 xd = tex2D(_Distort, i.worldPos.zy * _DistortScale);
                    float3 zd = tex2D(_Distort, i.worldPos.xy * _DistortScale);

                    // lerped together all sides for distort texture
                    float3 distorttexture = zd;
                    distorttexture = lerp(distorttexture, xd, blendNormal.x);


                    // normal noise triplanar for x, y, z sides
                    float3 xn = tex2D(_Noise, (i.worldPos.zy * _Scale));
                    float3 zn = tex2D(_Noise, (i.worldPos.xy  * _Scale));

                    // lerped together all sides for noise texture
                    float3 noisetexture = zn;
                    noisetexture = lerp(noisetexture, xn, blendNormal.x);

                    float particleAgePercent = i.uv.z;
                    particleAgePercent -= _Particle;

                    float3 finalNoise;
    #if MULTIPLY
                    finalNoise = noisetexture * distorttexture * 2;
    #else
                    finalNoise = (noisetexture + distorttexture) * 2;
    #endif
                    // particle shape
                    float4 col = tex2D(_MainTex, i.uv);

                    float4 result = smoothstep(particleAgePercent - _Cutoff,particleAgePercent, finalNoise.r* col.a);
                    float edge = result * step(finalNoise.r * col.a, particleAgePercent + _EdgeWidth) * col.a;// edge multiplied by particle shape  alpha

                    result *= col.a * result;// use particle texture
                    result += (result * _Brightness);// extra brightness

                    result *= _Tint;// tint
                    result *= i.color.a; // particle alpha
                    result += (edge * _EdgeColor);// add colored edge
                    // apply fog
                    UNITY_APPLY_FOG(i.fogCoord, result);
                    return result;

                }
                ENDCG
            }
        }
}