给我写一个云朵的shader
时间: 2024-05-12 11:12:59 浏览: 15
好的,以下是一个简单的云朵shader示例:
```
Shader "Custom/Clouds" {
Properties {
_MainTex ("Texture", 2D) = "white" {}
_CloudSpeed ("Cloud Speed", Range(0.01, 0.5)) = 0.1
_CloudDensity ("Cloud Density", Range(0.1, 1.0)) = 0.5
_CloudCoverage ("Cloud Coverage", Range(0.1, 1.0)) = 0.5
_CloudSharpness ("Cloud Sharpness", Range(0.1, 1.0)) = 0.5
_CloudColor ("Cloud Color", Color) = (1, 1, 1, 1)
}
SubShader {
Tags {"Queue"="Transparent" "RenderType"="Opaque"}
LOD 100
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata {
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f {
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float _CloudSpeed;
float _CloudDensity;
float _CloudCoverage;
float _CloudSharpness;
float4 _CloudColor;
float4 _MainTex_ST;
v2f vert (appdata v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
float4 frag (v2f i) : SV_Target {
float4 texel = tex2D(_MainTex, i.uv);
float time = _Time.y * _CloudSpeed;
float2 pos = i.uv * float2(10, 1) + float2(time, time * 0.2);
float noise = tex2D(_MainTex, pos).r * _CloudDensity;
float coverage = smoothstep(_CloudCoverage, _CloudCoverage + 0.1, noise);
float sharpness = pow(coverage, _CloudSharpness);
return lerp(texel, _CloudColor, sharpness);
}
ENDCG
}
}
FallBack "Diffuse"
}
```
这个shader使用了一个主纹理 `_MainTex`,并通过 `_CloudSpeed`、`_CloudDensity`、`_CloudCoverage`、`_CloudSharpness` 和 `_CloudColor` 属性控制云朵的外观。在片元着色器中,我们使用 Perlin 噪声生成云朵形状,并将其与主纹理进行混合,以实现云朵的效果。