Blender Skybox Addon

What is a Skybox?

A skybox is a 360-degree environment that surrounds a 3D scene, simulating a realistic sky, space, or landscape background. Instead of rendering distant objects in real-time (which is computationally expensive), skyboxes use pre-rendered textures on a cube or sphere, creating the illusion of an infinite world.

Skybox Formats:

• Cubemap (6-sided texture) – Used in WebGL (Babylon.js, Three.js), Unity, Unreal Engine, and more.
• Equirectangular (360-degree panoramic texture) – Used in HDRI lighting and game engines.

Blender Skybox Addon: What It Does

The Blender Skybox Addon simplifies the process of:

✔ Generating procedural skyboxes (with clouds, stars, sun, etc.).

✔ Rendering cubemaps and equirectangular images for export.

✔ Seamlessly integrating skyboxes into WebGL, Unity, and other platforms.

With this addon, you can create high-quality skyboxes in minutes without relying on external images.

Installing the Blender Skybox Addon

To install the Skybox Addon in Blender:

1. Open Blender and go to Edit > Preferences > Add-ons.
2. Click Install and select the downloaded .zip file.
3. Enable the addon by checking the box.
4. Save preferences and close the menu.

Once installed, you’ll find the Skybox Generator in the World Properties tab.

Creating a Skybox in Blender

1. Adding a Procedural Skybox

After enabling the addon:

1. Go to the World Properties tab.
2. Click Add Skybox to generate a procedural sky.
3. Adjust parameters like:

• Cloud Density
• Sun Position & Size
• Sky Color & Gradient
• Stars & Night Sky Effects

2. Rendering a Skybox (Cubemap or Equirectangular)

To render the skybox as a texture:

1. Switch to Cycles Renderer for best quality.
2. Open Camera Properties and set the projection to Panoramic.
3. Choose either:

• Equirectangular (for a single 360-degree image).
• Cube Map (for a 6-sided texture).

1. Render the image (F12) and save it as a .HDR, .PNG, or .EXR.

Exporting the Skybox for WebGL or Game Engines

1. Exporting a Cubemap for Babylon.js or Three.js

Most WebGL engines use a cubemap format (6 images for each face of a cube).

1. Render the Cubemap in Blender.
2. Save the 6 images (front, back, left, right, top, bottom).
3. Use the following code to load the cubemap in Babylon.js:

js

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const skybox = BABYLON.MeshBuilder.CreateBox("skyBox", {size: 1000}, scene);
const skyboxMaterial = new BABYLON.StandardMaterial("skyBoxMaterial", scene);
skyboxMaterial.reflectionTexture = new BABYLON.CubeTexture("textures/skybox", scene);
skyboxMaterial.backFaceCulling = false;
skybox.material = skyboxMaterial;

For Three.js, use:

js

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const loader = new THREE.CubeTextureLoader();
const skyboxTexture = loader.load([
    'textures/px.jpg', 'textures/nx.jpg', 
    'textures/py.jpg', 'textures/ny.jpg', 
    'textures/pz.jpg', 'textures/nz.jpg'
]);
scene.background = skyboxTexture;

2. Using an Equirectangular Skybox in Unity

For Unity, export an HDRI (Equirectangular) texture:

1. Set the Camera Projection to Equirectangular in Blender.
2. Render the image and save it as .HDR.
3. In Unity, go to Window > Lighting > Environment and set the Skybox Material to use the HDR texture.

Performance Optimization Tips

✔ Use compressed textures (.HDR, .EXR) instead of high-res .PNG for faster loading.

✔ Reduce texture size (e.g., 1024×1024 instead of 4096×4096) for mobile performance.

✔ Use DDS format for WebGL to improve texture loading speeds.

✔ Optimize UV mapping to avoid distortion in cubemaps.