A resource referenced in a [Sky] that is used to draw a background. The Panorama sky material functions similar to skyboxes in other engines, except it uses an equirectangular sky map instead of a cubemap.
Using an HDR panorama is strongly recommended for accurate, high-quality reflections. Godot supports the Radiance HDR ([code].hdr[/code]) and OpenEXR ([code].exr[/code]) image formats for this purpose.
You can use [url=https://danilw.github.io/GLSL-howto/cubemap_to_panorama_js/cubemap_to_panorama.html]this tool[/url] to convert a cubemap to an equirectangular sky map.