ThreeJS - Extend Lambert Shader with Custom VertexShader - three.js

Question

I want to adapt this Shader here:
https://aerotwist.com/tutorials/an-introduction-to-shaders-part-2/
to a standard Lambert or Phong that it works with all my Lights in the Scene.
My current state is that I extend the Lambert with this code:
var attributes = {
displacement: {
type: 'f', // a float
value: [] // an empty array
}
};
var uniforms = {
amplitude: {
type: 'f', // a float
value: 0
}
};
var shaders = { mylambert : THREE.ShaderLib[ 'lambert' ] };
var materials = {};
materials.mylambert = function( parameters, myUniforms ) {
var material = new THREE.ShaderMaterial( {
vertexShader: $('#vertexLambert').text(),
fragmentShader: shaders.mylambert.fragmentShader,
uniforms: THREE.UniformsUtils.merge( [ shaders.mylambert.uniforms, myUniforms ] ),
attributes :attributes,
lights:true,
shading:THREE.FlatShading
} );
material.setValues( parameters );
return material;
};
var myProperties = {
lights: true,
fog: true,
transparent: true
};
var myMaterial = new materials.mylambert( myProperties, uniforms );
Which I got from this Post:
extending lambert material, opacity not working
The vertexShader is basically the shape as shaders.mylambert.vertexShader but with the additional code from the shader example on top.
It works somehow, so the vertices move, but the faces didn't shade when they change their shape so they always have the same shader when I use a plane for example as a the mesh.
In short;
I need a Lambert/Phong Shader that manipulates the Vertices over time up and down to simulate a low Poly Water surface.

Answer 1

If this is still relevant, You can solve this issue much simpler:
Have your model render with a Lambert, Phong, Standard or whatever lit material you like.
Create another Scene, Camera and a WebGLRenderTarget, create a plane and apply your ShaderMaterial to it. Position your camera so that the plane fits exactly your entire frame of the scene.
Render the other Scene to the WebGlRenderTarget and apply it as a map to your original Lambert material this way:
let mat = new THREE.MeshLambertMaterial({
map: renderTarget.texture
})
Viola! You now have a fully lit ShaderMaterial as you like.