Unity Kajiya Hair Shader Corrected by Vert Normals

Posted 2020-06-20 bearworks

 

 

Shader "HairShader"
{
Properties
{
_MainTex ("Diffuse (RGB) Alpha (A)", 2D) = "white" {}
_Color ("Main Color", Color) = (0,0,0,1)
_SpecularTex ("Specular (R) Gloss (G) Anisotropic Mask (B)", 2D) = "gray" {}
_SpecularMultiplierT ("Specular Multiplier T", float) = 5.0
_SpecularMultiplierN ("Specular Multiplier N", float) = 10.0
_SpecularColor ("Specular Color", Color) = (0.5,0.5,0.5,1)
_Cutoff ("Alpha Cut-Off Threshold", float) = 0.5
_GlossInterp ( "Gloss Interploter", Range(-1,1)) = 0
_WaveSpeed ("Wave Speed", Vector) = (1,1,1,1)
_WaveSize ("Wave Size", float) = 0.1
_WavePhase ("Wave Phase", float) = 0.02
}

SubShader
{
Tags {"Queue"="Geometry" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}

Cull Off
ZWrite On
ZTest LEqual

CGPROGRAM
#pragma surface surf Aniso vertex:vert
#pragma target 3.0

struct SurfaceOutputAniso
{
fixed3 Albedo;
fixed3 Normal;
fixed3 Emission;
half Specular;
fixed Gloss;
fixed Alpha;
fixed AnisoMask;

half3 tangentV;
};

struct Input
{
float2 uv_MainTex;
half3 tangentV;
};

float4 _WaveSpeed;
float _WaveSize;
float _WavePhase;

void vert(inout appdata_full v, out Input o)
{
UNITY_INITIALIZE_OUTPUT(Input, o);

float3 waves = _WaveSize * v.tangent.xyz;
float3 freq = _Time.y * _WaveSpeed.xyz;
v.vertex.xyz += cos(freq + v.vertex.xyz * _WavePhase) * waves;
o.tangentV = v.tangent.xyz;
}

sampler2D _MainTex, _SpecularTex;
float _SpecularMultiplierT,_SpecularMultiplierN, _GlossInterp, _Cutoff;
fixed4 _SpecularColor, _Color;

void surf (Input IN, inout SurfaceOutputAniso o)
{
fixed4 albedo = tex2D(_MainTex, IN.uv_MainTex);
o.Albedo = lerp(albedo.rgb,albedo.rgb*_Color.rgb,0.5);
o.Alpha = albedo.a;
clip (o.Alpha - _Cutoff);
fixed3 spec = tex2D(_SpecularTex, IN.uv_MainTex).rgb;
o.Specular = spec.r;
o.Gloss = spec.g;
o.AnisoMask = spec.b;
o.tangentV = IN.tangentV;
}

inline fixed4 LightingAniso (SurfaceOutputAniso s, fixed3 lightDir, fixed3 viewDir, fixed atten)
{
half3 h = normalize(lightDir + viewDir);
float NdotL = saturate(dot(s.Normal, lightDir));

half3 T = normalize(cross( s.Normal, s.tangentV));
half3 L = normalize(lightDir);
half3 V = -normalize(viewDir);

float sq1 = (1.0-abs(dot(T, L)));
float sq2 = (1.0-abs(dot(T, V)));
float aniso = abs(dot(T,L) * dot(s.Normal,V));
aniso += sq1 * sq2;
aniso = pow(aniso, _SpecularMultiplierT);

float blinn = pow(dot(s.Normal, h), _SpecularMultiplierN) * s.Gloss;

float spec = saturate(lerp(blinn, aniso, s.AnisoMask + _GlossInterp) * s.Specular) * _SpecularColor;

fixed4 c;
c.rgb = spec;
c.a = s.Alpha;
return c;
}
ENDCG


}
FallBack Off
}