最近学了顶点片元Shader基本语法之后,决定拿一个Shader来分析一下,初学Shader,在此记录一下!
这个Shader效果都是在frag里进行;(不是说好了frag里计算量大要避免吗!!)
sampler2D _MainTex;
float _WaveStrength;
float _WaveFactor;
float _TimeScale;
fixed4 frag(v2f IN):COLOR
{
//计算出fixed2(0.5,0.5)到uv每个点的单位向量及方向
fixed2 uvDir = normalize(IN.uv-fixed2(0.5,0.5));
//计算出fixed2(0.5,0.5)到uv每个点的距离
fixed dis = distance(IN.uv,fixed2(0.5,0.5));
//加入uv偏移值
fixed2 uv = IN.uv+_WaveStrength*uvDir*sin(_Time.y*_TimeScale+dis*_WaveFactor);
return tex2D(_MainTex, uv);
}
- Sin函数取值范围在(-1,1)之间;
- _WaveStrength * uvDir控制偏移量的大小范围和方向;
Sin函数的变量为_Time.y,随着时间变化,Sin值会在(-1,1)之间变化,偏移量大小就会在(-_WaveStrength,WaveStrength)之间 变化;
效果图如下
Shader
Shader "Study/WaterWave1" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_WaveStrength("Wave Strength",Float) = 0.01
_WaveFactor("Wave Factor",Float) = 50
_TimeScale("Time Scale",Float) = 10
}
SubShader {
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f {
float4 vertex:SV_POSITION;
float2 uv:TEXCOORD0;
};
sampler2D _MainTex;
float _WaveStrength;
float _WaveFactor;
float _TimeScale;
v2f vert (appdata v)
{
v2f o;
o.uv = v.uv;
o.vertex = UnityObjectToClipPos(v.vertex);
return o;
}
fixed4 frag(v2f IN):COLOR
{
//计算出fixed2(0.5,0.5)到uv每个点的单位向量方向
fixed2 uvDir = normalize(IN.uv-fixed2(0.5,0.5));
//计算出fixed2(0.5,0.5)到uv每个点的距离
fixed dis = distance(IN.uv,fixed2(0.5,0.5));
fixed2 uv = IN.uv+_WaveStrength*uvDir*sin(_Time.y*_TimeScale+dis*_WaveFactor);
return tex2D(_MainTex, uv);
}
ENDCG
}
}
FallBack "Diffuse"
}