koobas.hobune.stream
Adding shadows to transparent shader?
Hey everyone, I've been try to learn shaders, In vain I should probably add. I want to learn shaders so I could add shadows to the "CumulusPerlinLayer" that comes with Unisky. If you don't know the shader, here it is.
Shader "Cumulus Perlin Layer"
{
Properties
{
// Texture used to generate perlin noise
_NoiseTexture("Noise Texture", 2D) = "white" {}
// This is the calculated illumination for the clouds
_IllumReference("Illumination Texture", 2D) = "white" {}
_SunColor("Sun Color", Vector) = (0,0,0,0)
_CloudCover("Cloud Cover", float) = 0
_SunAngle("Sun's Angle", float) = 0
_PrecipLevel("Precipitation Level", float) = 0
_Speed("Cloud Speed", Vector) = (0,0,0)
_ColorVar1("Color Variance 1", Vector) = (0,0,0)
_ColorVar2("Color Variance 2", Vector) = (0,0,0)
_GlowVar("Glow Variance", float) = 0
_ViewDistance("View Distance", float) = 0
_FogDensity("Fog Density", float) = 0
// We use this for the simulated atmospheric scattering
_v3CameraPos("Camera Position",Vector) = (0,0,0)
}
Subshader
{
Tags { "RenderType"="Geometry" "Queue" = "Transparent+1"}
Fog { Mode Off }
Pass
{
Blend SrcAlpha OneMinusSrcAlpha
ZWrite Off
Cull Back
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 3.0
#include "UnityCG.cginc"
#define ONE 1.0/128.0
#define ONEHALF 0.5/128.0
sampler2D _IllumReference;
sampler2D _NoiseTexture;
float4 _SunColor;
float _CloudCover;
float Time;
float _SunAngle;
float _PrecipLevel;
float3 _Speed;
float3 _ColorVar1;
float3 _ColorVar2;
float _ViewDistance;
float _GlowVar;
float _FogDensity;
float4 _v3CameraPos;
struct appdata_v
{
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
float3 vertPos : COLOR0;
};
struct v2f
{
float2 texCoord : TEXCOORD0;
float3 vertPos : COLOR0;
float4 pos : SV_POSITION;
float3 t0 : TEXCOORD1;
};
float4 randNum (float2 co)
{
return tex2D(_NoiseTexture, co).rgba;
}
float fade(float t)
{
return t*t*t*(t*(t*6.0-15.0)+10.0);
}
float Noise3D(float3 P)
{
float3 Pi = ONE*floor(P)+ONEHALF;
float3 Pf = frac(P);
float perm00 = randNum(Pi.xy).a ;
float3 grad000 = randNum(float2(perm00, Pi.z)).rgb * 4.0 - 1.0;
float n000 = dot(grad000, Pf);
float3 grad001 = randNum(float2(perm00, Pi.z + ONE)).rgb * 4.0 - 1.0;
float n001 = dot(grad001, Pf - float3(0.0, 0.0, 1.0));
float perm01 = randNum(Pi.xy + float2(0.0, ONE)).a;
float3 grad010 = randNum(float2(perm01, Pi.z)).rgb * 4.0 - 1.0;
float n010 = dot(grad010, Pf - float3(0.0, 1.0, 0.0));
float3 grad011 = randNum(float2(perm01, Pi.z + ONE)).rgb * 4.0 - 1.0;
float n011 = dot(grad011, Pf - float3(0.0, 1.0, 1.0));
float perm10 = randNum(Pi.xy + float2(ONE, 0.0)).a ;
float3 grad100 = randNum(float2(perm10, Pi.z)).rgb * 4.0 - 1.0;
float n100 = dot(grad100, Pf - float3(1.0, 0.0, 0.0));
float3 grad101 = randNum(float2(perm10, Pi.z + ONE)).rgb * 4.0 - 1.0;
float n101 = dot(grad101, Pf - float3(1.0, 0.0, 1.0));
float perm11 = randNum(Pi.xy + float2(ONE, ONE)).a ;
float3 grad110 = randNum(float2(perm11, Pi.z)).rgb * 4.0 - 1.0;
float n110 = dot(grad110, Pf - float3(1.0, 1.0, 0.0));
float3 grad111 = randNum(float2(perm11, Pi.z + ONE)).rgb * 4.0 - 1.0;
float n111 = dot(grad111, Pf - float3(1.0, 1.0, 1.0));
float4 n_x = lerp(float4(n000, n001, n010, n011),
float4(n100, n101, n110, n111), fade(Pf.x));
float2 n_xy = lerp(n_x.xy, n_x.zw, fade(Pf.y));
float n_xyz = lerp(n_xy.x, n_xy.y, fade(Pf.z));
return n_xyz;
}
v2f vert (appdata_v v)
{
v2f o;
o.pos = mul( UNITY_MATRIX_MVP, v.vertex);
o.texCoord = v.texcoord;
o.vertPos.rg = o.texCoord;
o.vertPos.b = 0;
o.pos = mul (UNITY_MATRIX_MVP, v.vertex/20);
o.t0 = (float3(0, 44931.74, 0) - mul(v.vertex, _Object2World)).xyz;
return o;
}
half4 frag (v2f i) : COLOR
{
// static var - edit this variable to change the scale of the clouds
float scale = 60;
float3 vertexpos = i.vertPos.xyz;
// var
float3 DSpeed = float3(_Speed.x,_Speed.y,_Speed.z);
float clouds = 1.4f;
clouds += Noise3D((vertexpos*scale)+(clouds*0.14)+(Time*DSpeed))*1.1;
clouds += abs(Noise3D(((vertexpos*scale+(clouds*0.14))+(Time*DSpeed))*4.0)/4.0);
clouds += abs(Noise3D(((vertexpos*scale+(clouds*0.18))+(Time*DSpeed))*8.0)/8.0);
clouds += abs(Noise3D(((vertexpos*scale+(clouds*0.16))+(Time*DSpeed))*16.0)/16.0);
clouds += abs(Noise3D(((vertexpos*scale+(clouds*0.16))+(Time*DSpeed))*32.0)/32.0);
clouds += abs(Noise3D(((vertexpos*scale+(clouds*0.16))+(Time*DSpeed))*64.0)/64.0);
// var
clouds += _CloudCover;
float4 retColor = float4(0,0,0,0);
retColor.a = clouds;
// var (cloud color variance 1)
retColor.rgb = _ColorVar1 - retColor.rgb;
if(_SunAngle <= 0 && retColor.a > 0)
retColor.rgb /= lerp(retColor.a, 1, - _CloudCover * (1 - abs(_SunAngle)));
if(retColor.a > 0 && _SunAngle > 0)
retColor.rgb /= lerp(retColor.a, 1, -_CloudCover * (1 - _SunAngle));
// var (cloud color variance 2)
retColor.rgb = lerp(float3(1,1,1), retColor.rgb, _ColorVar2);
retColor.rgb *= _SunColor.rgb;
// var (cloud color glow variance)
retColor.a *= (_GlowVar-retColor.r);
// var (cloud precipitation)
retColor.rgb = lerp(float3(0,0,0), retColor.rgb, _PrecipLevel);
// var (atmosphere visibility distance)
if(retColor.a > 0)
retColor.a *= 1 - ((length(i.t0)*length(i.t0))/70000000 * _ViewDistance);
return retColor;
}
ENDCG
}
}
}
If anyone could show me show to make the perlin noise generated clouds cast shadows, I would be extremely greatful.
Thanks Tz
