// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'
Shader "Unity Shaders Book/Chapter 11/Vertex Animation With Shadow"
{
Properties
{
//河流纹理
_MainTex ("Main Tex", 2D) = "white" {}
//控制整体颜色
_Color ("Color Tint", Color) = (1,1,1,1)
//控制水流波动的幅度
_Magnitude ("Distortion Magnitude", Float) = 1
//控制水流波动的频率
_Frequency ("Distortion Frequency", Float) = 1
//控制波长的倒数，倒数越大，波长越小
_InvWaveLength ("Distortion Inverse Wave Length", Float) = 10
//河流纹理的移动速度
_Speed ("Speed",Float) = 0.5
}
SubShader
{
//由于序列帧图像通常是透明背景，所以需要设置pass的相关状态，以渲染透明效果
//半透明“标配”,DisableBatching指明是否对该SubShader使用批处理，批处理会合并所有相关模型，模型各自的模型空间就会丢失
Tags{ "Queue" = "Transparent" "IgnoreProject" = "True" "RenderType" = "Transparent" "DisableBatching" = "True"}
//此Pass用于顶点动画
Pass
{
Tags{ "LightMode" = "ForwardBase" }
//为了让水流的每个面都能显示
//关闭深度写入
ZWrite off
//开启并设置混合模式
Blend SrcAlpha OneMinusSrcAlpha
//关闭剔除功能
Cull Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
#pragma multi_compile_fog
#include "UnityCG.cginc"
sampler2D _MainTex;
float4 _MainTex_ST;
float4 _Color;
float _Magnitude;
float _Frequency;
float _InvWaveLength;
float _Speed;
struct a2v
{
float4 vertex : POSITION;
float4 texcoord : TEXCOORD0;
};
struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
v2f vert (a2v v)
{
v2f o;
float4 offset;
offset.yzw = float3(0.0, 0.0, 0.0);
//_Frequency*_Time.y控制正弦函数频率
//加上模型空间下的分量乘以_InvWaveLength位置控制不同位置具有不同的位移
//乘以_Magnitude控制波动幅度
offset.x = sin(_Frequency * _Time.y + v.vertex.x * _InvWaveLength + v.vertex.y * _InvWaveLength + v.vertex.z * _InvWaveLength) * _Magnitude;
//把位移量添加到顶点位置上
o.pos = UnityObjectToClipPos(v.vertex + offset);
//进行纹理动画，使用_Time.y和_Speed控制水平方向上的位移
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
o.uv += float2(0.0, _Time.y * _Speed);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
//对纹理进行简单采样
fixed4 c = tex2D(_MainTex, i.uv);
// 添加颜色控制
c.rgb *= _Color.rgb;
return c;
}
ENDCG
}
//此Pass用于渲染动画的阴影
Pass
{
//绘制阴影都需要调用ShadowCaster
Tags { "LightMode"="ShadowCaster" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_comlile_shadowCaster
#include "UnityCG.cginc"
float _Magnitude;
float _Frequency;
float _InvWaveLength;
float _Speed;
struct a2v {
//使用TRANSFER_SHADOW_CASTER_NORMALOFFSET必须包含v.vertex和v.normal
float4 vertex : POSITION;
float4 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct v2f {
//定义阴影投射需要的变量
V2F_SHADOW_CASTER;
};
v2f vert(a2v v) {
v2f o;
//按顶点动画Pass中的处理方法计算顶点偏移值
float4 offset;
offset.yzw = float3(0, 0, 0);
offset.x = sin(_Frequency * _Time.y + v.vertex.x * _InvWaveLength + v.vertex.y * _InvWaveLength + v.vertex.z * _InvWaveLength) * _Magnitude;
//直接把偏移值加到顶点位置变量中
v.vertex = v.vertex + offset;
//使用宏完成阴影偏移
TRANSFER_SHADOW_CASTER_NORMALOFFSET(o);
return o;
}
fixed4 frag(v2f i) : SV_Target{
//使用宏完成阴影投射
SHADOW_CASTER_FRAGMENT(i);
}
ENDCG
}
}
Fallback"VertexLit"
}
