this reflectiontexture isn't working, not because there's no image 404 but there's something wrong with all the params set in general for oceanic waves thats how they should look like. except images, try use some existing skybox gradient as skybox for actual wave reflection.: <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Transparent Reflectorious Waves with Sun and Sky</title>
<style>
body {
margin: 0;
}

canvas {
display: block;
}
</style>
</head>

<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/0.152.2/three.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/simplex-noise/2.4.0/simplex-noise.min.js"></script>

<script>
// Set up the scene, camera, and renderer
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

// Set up the terrain geometry
const width = 500;
const height = 100;
const widthSegments = 32;
const heightSegments = 16;
const geometry = new THREE.PlaneBufferGeometry(width, height, widthSegments, heightSegments);
const positions = geometry.getAttribute("position").array;
const simplex = new SimplexNoise(Math.random());

// Create a color gradient based on the height of each vertex
function colorGradient(height) {
const deepWaterColor = new THREE.Color(0x2e3e50);
const shallowWaterColor = new THREE.Color(0x2e3e50);
const color = deepWaterColor.lerp(shallowWaterColor, Math.min(height / 5, 1));
color.lerp(new THREE.Color(0xffffff), Math.max(0, (height - 0.1) / 3));
return color;
}

// Generate the terrain mesh with vertex colors based on the color gradient
function generateTerrain(positions, scale = 0.1, elevation = 0.1) {
const colors = new Float32Array(positions.length);
geometry.setAttribute("color", new THREE.BufferAttribute(colors, 3));

for (let i = 0; i < positions.length; i += 3) {
const nx = positions[i] * scale;
const ny = positions[i + 1] * scale;
const height = (simplex.noise2D(nx, ny) + 1) * 0.1 * elevation;
positions[i + 2] = height;

const vertexColor = colorGradient(height);
colors[i] = vertexColor.r;
colors[i + 1] = vertexColor.g;
colors[i + 2] = vertexColor.b;
}

geometry.computeVertexNormals();
}

generateTerrain(positions);

// Create the material for the waves, with transparency and reflections
const reflectionTexture = new THREE.CubeTextureLoader()
.setPath("https://filterforge.com/filters/7414.jpg")
.load(["px.jpg", "nx.jpg", "py.jpg", "ny.jpg", "pz.jpg", "nz.jpg"]);

const material = new THREE.MeshPhongMaterial({
vertexColors: false,
side: THREE.DoubleSide,
transparent: true,
opacity: 0.5,
envMap: reflectionTexture,
combine: THREE.AddOperation,
reflectivity: 1.0,
});

// Create the terrain mesh and add it to the scene
const terrain = new THREE.Mesh(geometry, material);
terrain.rotation.x = Math.PI / 2;
scene.add(terrain);

// Add the sun and its light to the scene
const sunSphere = new THREE.SphereGeometry(128, 16, 16);
const sunMaterial = new THREE.MeshBasicMaterial({
color: 0xfff8c4,
transparent: false,
opacity: 0.999,
blending: THREE.CustomBlending,
blendSrc: THREE.SrcAlphaFactor,
blendDst: THREE.OneMinusSrcColorFactor,
depthTest: true,
});

const sun = new THREE.Mesh(sunSphere, sunMaterial);

function setSunPosition(dayProgress) {
const x = 0;
const y = 300 - (dayProgress * 500);
const z = -500;
sun.position.set(x, y, z);
}

const sunLight = new THREE.PointLight(0xffffcc, 1);

function addSunToScene(state) {
if (state) {
scene.add(sun);
scene.add(sunLight);
} else {
scene.remove(sun);
scene.remove(sunLight);
}
}

addSunToScene(true);

let sunVisible = true;

// Create the sky gradient with clouds and add it to the scene
const skyColor = new THREE.Color(0xffffff);

function createSkyGradient() {
const skyGeometry = new THREE.SphereBufferGeometry(250, 128, 128);
const skyMaterial = new THREE.MeshBasicMaterial({
vertexColors: true,
side: THREE.BackSide,
});

const cloudColorTop = new THREE.Color(0xffffff);
const cloudColorBottom = new THREE.Color(0xadd8e6);

const colors = [];

for (let i = 0; i < skyGeometry.attributes.position.count; i++) {
const color = new THREE.Color(0xffffff);
const point = new THREE.Vector3();

point.fromBufferAttribute(skyGeometry.attributes.position, i);

const distance = point.distanceTo(new THREE.Vector3(0, 0, 0));
const percent = distance / (skyGeometry.parameters.radius * 1.2);

color.lerpColors(skyColor, skyColor, percent);

const cloudColor = new THREE.Color(0xffffff);
const cloudPercent = distance / skyGeometry.parameters.radius;
cloudColor.lerpColors(cloudColorBottom, cloudColorTop, cloudPercent);

const noise = (Math.random() * 0.1) - 0.5;
cloudColor.offsetHSL(0, 0, noise);

const alpha = Math.random() * 0.06;
const finalColor = new THREE.Color();
finalColor.lerpColors(color, cloudColor, alpha);

colors.push(finalColor.r, finalColor.g, finalColor.b);
}

skyGeometry.setAttribute("color", new THREE.Float32BufferAttribute(colors, 3));

const skyMesh = new THREE.Mesh(skyGeometry, skyMaterial);
scene.add(skyMesh);

return skyMesh;
}

const sky = createSkyGradient();
scene.add(sky);

camera.position.z = 50;
camera.position.y = 5;
camera.rotation.x = -Math.PI / 10;

let clock = new THREE.Clock();

function updatePositions() {
const elapsedTime = clock.getElapsedTime();
const colors = geometry.getAttribute("color").array;

for (let i = 0; i < positions.length; i += 3) {
const nx = positions[i] * 0.1 + elapsedTime * 0.1;
const ny = positions[i + 1] * 0.1 + elapsedTime * 0.1;
const height = (simplex.noise2D(nx, ny) + 1) * 0.5 * 5;
positions[i + 2] = height;

const vertexColor = colorGradient(height);
colors[i] = vertexColor.r;
colors[i + 1] = vertexColor.g;
colors[i + 2] = vertexColor.b;
}

geometry.attributes.position.needsUpdate = true;
geometry.attributes.color.needsUpdate = true;
geometry.computeVertexNormals();
}

function updateSun() {
const elapsedTime = clock.getElapsedTime();
const dayProgress = elapsedTime % 10 / 10;
setSunPosition(dayProgress);
sunLight.position.copy(sun.position);
}

function animate() {
requestAnimationFrame(animate);
updatePositions();
updateSun();
renderer.render(scene, camera);
}

animate();
</script>
</body>

</html>