大部分天气插件中都包含动态云，有的项目不需要完整的插件，只包含云的效果可以使用这个。
从Unity插件Pure Natrue中提取出来的效果。Pure Nature：https://assetstore.unity.com/packages/3d/environments/pure-nature-188246
Clouds.shader
Shader "Custom/Clouds"
{
Properties
{
_ViewDistance("View Distance", Float) = 5000
_DirectionSpeed("Direction / Speed", Vector) = (20,5,10,-5)
[Header(Main)][Space(10)]_Noise01("Noise 01", 2D) = "white" {}
_Tiling01("Tiling", Float) = 0.02
_Noise01Power("Power", Range( 0 , 1)) = 0.75
[Space(30)]_Noise02("Noise 02", 2D) = "white" {}
_Tiling02("Tiling", Float) = 0.03
_Noise02Power("Power", Range( 0 , 1)) = 0.3
[Space(10)][Header(Clouds)][Space(10)]_ScatteringColor("Color", Color) = (1,1,1,1)
_Coverage("Coverage", Range( 0 , 1)) = 0.3
_Softness("Softness", Range( 0 , 1)) = 0.25
[Toggle(_USEFOG_ON)] _UseFog("Use Fog", Float) = 1
[Space(10)][Header(Scattering)][Space(10)]_CloudsColor("Color", Color) = (0.1843137,0.3568628,0.4627451,1)
[HideInInspector]_cloudsPosition("cloudsPosition", Float) = 1
_ScatteringPower("Absorption", Range( 0 , 50)) = 10
[HideInInspector]_cloudsHeight("cloudsHeight", Float) = 1
[HideInInspector] __dirty( "", Int ) = 1
}
SubShader
{
Tags{ "RenderType" = "Transparent" "Queue" = "Transparent+0" "IgnoreProjector" = "True" "ForceNoShadowCasting" = "True" "IsEmissive" = "true" }
Cull Off
CGINCLUDE
#include "UnityPBSLighting.cginc"
#include "UnityShaderVariables.cginc"
#include "UnityCG.cginc"
#include "Lighting.cginc"
#pragma target 3.0
#pragma shader_feature_local _USEFOG_ON
struct Input
{
float3 worldPos;
float eyeDepth;
};
struct SurfaceOutputCustomLightingCustom
{
half3 Albedo;
half3 Normal;
half3 Emission;
half Metallic;
half Smoothness;
half Occlusion;
half Alpha;
Input SurfInput;
UnityGIInput GIData;
};
uniform float _cloudsPosition;
uniform float _cloudsHeight;
uniform float _Coverage;
uniform float _ScatteringPower;
uniform float4 _ScatteringColor;
uniform float4 _CloudsColor;
uniform float _ViewDistance;
uniform sampler2D _Noise02;
uniform float4 _DirectionSpeed;
uniform float _Tiling02;
uniform sampler2D _Noise01;
uniform float _Tiling01;
uniform float _Noise01Power;
uniform float _Noise02Power;
uniform float _Softness;
void vertexDataFunc( inout appdata_full v, out Input o )
{
UNITY_INITIALIZE_OUTPUT( Input, o );
o.eyeDepth = -UnityObjectToViewPos( v.vertex.xyz ).z;
}
inline half4 LightingStandardCustomLighting( inout SurfaceOutputCustomLightingCustom s, half3 viewDir, UnityGI gi )
{
UnityGIInput data = s.GIData;
Input i = s.SurfInput;
half4 c = 0;
float cameraDepthFade66 = (( i.eyeDepth -_ProjectionParams.y - 0.0 ) / _ViewDistance);
float DistanceFade124 = ( 1.0 - cameraDepthFade66 );
float2 appendResult161 = (float2(_DirectionSpeed.z , _DirectionSpeed.w));
float3 ase_worldPos = i.worldPos;
float2 appendResult4 = (float2(ase_worldPos.x , ase_worldPos.z));
float2 panner159 = ( _Time.y * appendResult161 + appendResult4);
float3 temp_cast_1 = (tex2D( _Noise02, ( panner159 * ( _Tiling02 / 10000.0 ) ) ).r).xxx;
float3 temp_cast_2 = (tex2D( _Noise02, ( panner159 * ( _Tiling02 / 10000.0 ) ) ).r).xxx;
float3 linearToGamma92 = LinearToGammaSpace( temp_cast_2 );
float2 appendResult160 = (float2(_DirectionSpeed.x , _DirectionSpeed.y));
float2 panner157 = ( _Time.y * appendResult160 + appendResult4);
float3 temp_cast_3 = (tex2D( _Noise01, ( panner157 * ( _Tiling01 / 10000.0 ) ) ).r).xxx;
float3 temp_cast_4 = (tex2D( _Noise01, ( panner157 * ( _Tiling01 / 10000.0 ) ) ).r).xxx;
float3 linearToGamma91 = LinearToGammaSpace( temp_cast_4 );
float3 blendOpSrc155 = linearToGamma92;
float3 blendOpDest155 = ( linearToGamma91 * _Noise01Power );
float3 lerpBlendMode155 = lerp(blendOpDest155, max( blendOpSrc155, blendOpDest155 ),_Noise02Power);
float3 Noise121 = ( saturate( lerpBlendMode155 ));
float Coverage211 = _Coverage;
float CloudHeight130 = ( 1.0 - pow( saturate( ( abs( ( _cloudsPosition - ase_worldPos.y ) ) / _cloudsHeight ) ) , ( 1.0 - Coverage211 ) ) );
float3 temp_cast_5 = (( 1.0 - (0.0 + (Coverage211 - 0.0) * (1.0 - 0.0) / (0.98 - 0.0)) )).xxx;
float3 temp_cast_6 = (_Softness).xxx;
float3 CloudCoverage134 = pow( saturate( (float3( 0,0,0 ) + (( Noise121 * CloudHeight130 ) - temp_cast_5) * (float3( 1,0,0 ) - float3( 0,0,0 )) / (float3( 1,0,0 ) - temp_cast_5)) ) , temp_cast_6 );
c.rgb = 0;
c.a = saturate( ( DistanceFade124 * CloudCoverage134 ) ).x;
return c;
}
inline void LightingStandardCustomLighting_GI( inout SurfaceOutputCustomLightingCustom s, UnityGIInput data, inout UnityGI gi )
{
s.GIData = data;
}
void surf( Input i , inout SurfaceOutputCustomLightingCustom o )
{
o.SurfInput = i;
#if defined(LIGHTMAP_ON) && ( UNITY_VERSION < 560 || ( defined(LIGHTMAP_SHADOW_MIXING) && !defined(SHADOWS_SHADOWMASK) && defined(SHADOWS_SCREEN) ) )//aselc
float4 ase_lightColor = 0;
#else //aselc
float4 ase_lightColor = _LightColor0;
#endif //aselc
float3 ase_worldPos = i.worldPos;
float3 ase_worldViewDir = Unity_SafeNormalize( UnityWorldSpaceViewDir( ase_worldPos ) );
#if defined(LIGHTMAP_ON) && UNITY_VERSION < 560 //aseld
float3 ase_worldlightDir = 0;
#else //aseld
float3 ase_worldlightDir = normalize( UnityWorldSpaceLightDir( ase_worldPos ) );
#endif //aseld
float dotResult109 = dot( ase_worldViewDir , -ase_worldlightDir );
float temp_output_114_0 = pow( saturate( dotResult109 ) , 5.0 );
float Coverage211 = _Coverage;
float CloudHeight130 = ( 1.0 - pow( saturate( ( abs( ( _cloudsPosition - ase_worldPos.y ) ) / _cloudsHeight ) ) , ( 1.0 - Coverage211 ) ) );
float temp_output_197_0 = pow( ( 1 * CloudHeight130 ) , _ScatteringPower );
float4 Scattering119 = ( ( ( ase_lightColor * temp_output_114_0 ) + ( temp_output_114_0 * unity_AmbientSky * ase_lightColor ) ) * temp_output_197_0 );
float Lerp223 = temp_output_197_0;
float cameraDepthFade66 = (( i.eyeDepth -_ProjectionParams.y - 0.0 ) / _ViewDistance);
float DistanceFade124 = ( 1.0 - cameraDepthFade66 );
#ifdef _USEFOG_ON
float staticSwitch192 = saturate( ( DistanceFade124 / 1.0 ) );
#else
float staticSwitch192 = 1.0;
#endif
float4 lerpResult181 = lerp( unity_FogColor , _CloudsColor , staticSwitch192);
float4 CloudLighting137 = ( Scattering119 + ( ( _ScatteringColor * Lerp223 ) + lerpResult181 ) );
o.Emission = CloudLighting137.rgb;
}
ENDCG
CGPROGRAM
#pragma surface surf StandardCustomLighting alpha:fade keepalpha fullforwardshadows nofog vertex:vertexDataFunc
ENDCG
Pass
{
Name "ShadowCaster"
Tags{ "LightMode" = "ShadowCaster" }
ZWrite On
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 3.0
#pragma multi_compile_shadowcaster
#pragma multi_compile UNITY_PASS_SHADOWCASTER
#pragma skip_variants FOG_LINEAR FOG_EXP FOG_EXP2
#include "HLSLSupport.cginc"
#if ( SHADER_API_D3D11 || SHADER_API_GLCORE || SHADER_API_GLES || SHADER_API_GLES3 || SHADER_API_METAL || SHADER_API_VULKAN )
#define CAN_SKIP_VPOS
#endif
#include "UnityCG.cginc"
#include "Lighting.cginc"
#include "UnityPBSLighting.cginc"
sampler3D _DitherMaskLOD;
struct v2f
{
V2F_SHADOW_CASTER;
float1 customPack1 : TEXCOORD1;
float3 worldPos : TEXCOORD2;
UNITY_VERTEX_INPUT_INSTANCE_ID
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert( appdata_full v )
{
v2f o;
UNITY_SETUP_INSTANCE_ID( v );
UNITY_INITIALIZE_OUTPUT( v2f, o );
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO( o );
UNITY_TRANSFER_INSTANCE_ID( v, o );
Input customInputData;
vertexDataFunc( v, customInputData );
float3 worldPos = mul( unity_ObjectToWorld, v.vertex ).xyz;
half3 worldNormal = UnityObjectToWorldNormal( v.normal );
o.customPack1.x = customInputData.eyeDepth;
o.worldPos = worldPos;
TRANSFER_SHADOW_CASTER_NORMALOFFSET( o )
return o;
}
half4 frag( v2f IN
#if !defined( CAN_SKIP_VPOS )
, UNITY_VPOS_TYPE vpos : VPOS
#endif
) : SV_Target
{
UNITY_SETUP_INSTANCE_ID( IN );
Input surfIN;
UNITY_INITIALIZE_OUTPUT( Input, surfIN );
surfIN.eyeDepth = IN.customPack1.x;
float3 worldPos = IN.worldPos;
half3 worldViewDir = normalize( UnityWorldSpaceViewDir( worldPos ) );
surfIN.worldPos = worldPos;
SurfaceOutputCustomLightingCustom o;
UNITY_INITIALIZE_OUTPUT( SurfaceOutputCustomLightingCustom, o )
surf( surfIN, o );
UnityGI gi;
UNITY_INITIALIZE_OUTPUT( UnityGI, gi );
o.Alpha = LightingStandardCustomLighting( o, worldViewDir, gi ).a;
#if defined( CAN_SKIP_VPOS )
float2 vpos = IN.pos;
#endif
half alphaRef = tex3D( _DitherMaskLOD, float3( vpos.xy * 0.25, o.Alpha * 0.9375 ) ).a;
clip( alphaRef - 0.01 );
SHADOW_CASTER_FRAGMENT( IN )
}
ENDCG
}
}
Fallback "Diffuse"
}
完整资源下载：horse7.cn/Download/VolumeClouds.unitypackage