my360place
An equirectangular panorama is already a skybox
Same file, three engines, and one honest caveat about lighting.
The virtual tour world and the game world buy the same file and call it two different things. A tour builder calls it an equirectangular panorama. A game developer calls it a skybox, or a 360 background, or a panoramic sky. It is the same 2:1 image either way, and it drops into an engine in about a minute.
Unity
Create a material and set its shader to Skybox/Panoramic. Assign your image as the texture, leave the mapping on latitude longitude layout, then set that material as the scene skybox under Lighting and Environment. That is the whole job.
Unreal Engine
Drop an HDRIBackdrop actor into the scene and give it the texture, which also gets you a ground plane that catches shadows. If you only want the sphere, use the image as the source texture on a Sky Light instead.
Blender
In World properties, add an Environment Texture node and load the image into it. It shows up in the viewport immediately and renders behind everything.
The caveat worth reading
There is a real difference between a background and a light source, and most listings do not tell you which one they are selling.
- A JPG is low dynamic range. It is perfect behind your scene, through a window, on a screen, or reflected in something. It is a picture.
- An HDR or EXR file carries brightness values far past white, which is what lets an engine light a whole scene from the sky. That is image based lighting, and a JPG cannot do it convincingly.
Everything in this catalogue is 8192 x 4096 JPG. So: excellent as a background, a reflection source or the view out of a window, and not a substitute for a proper HDRI if you are lighting an exterior from it. Worth saying plainly, because the two get sold as the same thing constantly.
On resolution
A lot of panoramic sky packs ship around 6000 x 3000. These are 8192 x 4096, which matters more in a headset than on a monitor, because in VR the image is a few centimetres from someone's eye and every missing pixel is visible.
If you want the format question answered properly, equirectangular versus cubemap versus HDRI is its own thing.
