Skybox
A cube or sphere of distant scenery around the camera, creating a whole world background without modeling the horizon.
See it
What it is
A skybox surrounds the camera with distant scenery, traditionally six images mapped to the inside faces of a cube. A skydome or an equirectangular panorama does the same job with different geometry. The background ignores camera translation but responds when the camera rotates, so it always appears infinitely far away.
Use one for skies, space, distant mountains, or a fast sense of place without modeling a huge world. A cubemap can also serve as an environment map for PBR reflections and image-based lighting, but showing it as the background and using it to light materials are separate scene settings. Free equirectangular HDRIs from Poly Haven are the usual starting point on the web.
Gotcha: a skybox has no parallax, so nearby buildings or trees painted into it look stuck to the camera as you move. Keep close scenery as real geometry. Cube faces also need the correct axis order and matching edge exposure; one rotated face or mismatched horizon produces an obvious seam.
Ask AI for it
Add a cubemap skybox to this three.js scene with CubeTextureLoader using the face order px, nx, py, ny, pz, nz. Assign the loaded CubeTexture to scene.background and scene.environment so MeshStandardMaterial objects can reflect it, set the CubeTexture colorSpace to THREE.SRGBColorSpace for the supplied LDR images, and add a chrome sphere that makes face orientation and seams easy to inspect.