Hey, so I am currently working on a project of my city, I am so into this that I even grabbed my neighbour’s gopro and with difficulty, made my own HDRI.
But then I realised, that the skybox has to be square so I went back and did it all again.
The reason why I made my own HDRI, is because I wanted to simulate realistic lighting, but do roblox skyboxes work as HDRIs?
From what I know, HDRIs on Roblox are currently not possible. You need to convert it in a 3rd party software to be able to be used on Roblox. I am not too experienced in this range, but I highly recommend you read this thread as it might answer your questions.