v2f vert (appdata v){v2f o;float4 worldPos = mul(unity_ObjectToWorld, v.vertex);//得到物体和草模型顶点之间的距离float dis = distance(_PlayerPos, worldPos);//通过影响范围，还有强度和UV的值来控制草的弯曲强度float pushDown = saturate((1 - dis + _PushRadius) * v.uv.y * _Strength);//计算出每个顶点散开的方向并做归一化处理float3 direction = normalize(worldPos.xyz - _PlayerPos.xyz);//减弱一些y轴向上的影响，否则很多草顶点会穿过地面direction.y *= 0.5;worldPos.xyz += direction * pushDown;o.pos = mul(UNITY_MATRIX_VP, worldPos);o.uv = v.uv;return o;}

Shader "Custom/GrassVertexAniInteractive"
{Properties{_MainTex ("Texture", 2D) = "white" {}_Noise("Noise", 2D) = "black" {}_WindControl("WindControl(x:XSpeed y:YSpeed z:ZSpeed w:windMagnitude)",vector) = (1,1,1,0.5)//前面几个分量表示在各个轴向上自身摆动的速度, w表示摆动的强度_WaveControl("WaveControl(x:XSpeed y:YSpeed z:ZSpeed w:worldSize)",vector) = (1,0,1,1)//前面几个分量表示在各个轴向上风浪的速度, w用来模拟地图的大小,值越小草摆动的越凌乱，越大摆动的越整体//_PlayerPos("PlayerPos", vector) = (0,0,0,0)//物体的位置坐标，需要在运行时通过C#代码传入，所以这里注释掉，把这个参数作为全局控制的参数_Strength("Strength", float) = 1//草地弯曲的强度_PushRadius("PushRadius", float) = 1//交互的范围}SubShader{Tags { "RenderType"="Opaque" }LOD 100Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag#pragma multi_compile_instancing#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;UNITY_VERTEX_INPUT_INSTANCE_ID};struct v2f{float2 uv : TEXCOORD0;float4 pos : SV_POSITION;};sampler2D _MainTex;sampler2D _Noise;half4 _WindControl;half4 _WaveControl;float4 _PlayerPos;half _Strength;half _PushRadius;v2f vert (appdata v){v2f o;UNITY_SETUP_INSTANCE_ID(v);//草地自身风吹草动的计算float4 worldPos = mul(unity_ObjectToWorld, v.vertex);float2 samplePos = worldPos.xz / _WaveControl.w;samplePos += _Time.x * -_WaveControl.xz;fixed waveSample = tex2Dlod(_Noise, float4(samplePos, 0, 0)).r;worldPos.x += sin(waveSample * _WindControl.x) * _WaveControl.x * _WindControl.w * v.uv.y;worldPos.z += sin(waveSample * _WindControl.z) * _WaveControl.z * _WindControl.w * v.uv.y;//草地交互的计算float dis = distance(_PlayerPos, worldPos);float pushDown = saturate((1 - dis + _PushRadius) * v.uv.y * _Strength);float3 direction = normalize(worldPos.xyz - _PlayerPos.xyz);direction.y *= 0.5;worldPos.xyz += direction * pushDown;o.pos = mul(UNITY_MATRIX_VP, worldPos);o.uv = v.uv;return o;}fixed4 frag (v2f i) : SV_Target{fixed4 col = tex2D(_MainTex, i.uv);return col;}ENDCG}}
}

void Update(){playerPos = transform.position;Shader.SetGlobalVector("_PlayerPos" , playerPos);}