Vertex displacement doesn't affect anything -- Unity - unity3d

Question

I'm trying to implement a simulation of an ocean based on this tutorial but I can't get my shader to affect my plane. It stays completly flat whatever I do.
This is my shader :
Shader "Custom/Waves"
{
Properties
{
_Color ("Color", Color) = (1,1,1,1)
_MainTex ("Albedo (RGB)", 2D) = "white" {}
_Glossiness ("Smoothness", Range(0,1)) = 0.5
_Metallic ("Metallic", Range(0,1)) = 0.0
_NormalMap ("Normal Map", 2D) = "bump" {}
//Wave Properties
_Direction("Direction", Vector) = (1.0, 0.0, 0.0, 1.0)
_Steepness("Steepness", Range(0.1,1.0)) = 0.5
_Freq("Frequency", Range(1.0,10.0)) = 1.0
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
#pragma surface surf Standard fullforwardshadows
// Use shader model 3.0 target, to get nicer looking lighting
#pragma target 3.0
sampler2D _MainTex;
float _Steepness, _Freq;
float4 _Direction;
struct Input
{
float2 uv_MainTex;
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
// Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
// See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
// #pragma instancing_options assumeuniformscaling
UNITY_INSTANCING_BUFFER_START(Props)
// put more per-instance properties here
UNITY_INSTANCING_BUFFER_END(Props)
void vert(inout appdata_full v){
float3 pos = v.vertex.xyz;
float4 dir = normalize(_Direction);
float defaultWavelength = 2 * UNITY_PI;
float wL = defaultWavelength / _Freq;
float phase = sqrt(9.8/wL);
float disp = wL * (dot(dir, pos) - (phase * _Time.y));
float peak = _Steepness/wL;
pos.x += dir.x * (peak * cos(disp));
pos.y = peak * sin(disp);
pos.z += dir.y * (peak * cos(disp));
v.vertex.xyz = pos;
}
void surf (Input IN, inout SurfaceOutputStandard o)
{
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
}
ENDCG
}
FallBack "Diffuse"
}
I thought that it might be the link between the plane, the material and the shader but it doesn't seem to help. I don't have any idea of what I did wrong. I tried with and without GPU instancing and it does not change anything.

Answer 1

You forgot to declare that you want to use a vertex function.
Add this before or after the other pragma
#pragma vertex vert