I'm trying to create a skybox and just wanted to ask, is there any way to load a cubemap from single png image (https://i.sstatic.net/73tCt.png something like this) using something like stb_image for example and copy contents of it to vulkan image? what I mean is do I have to go into photoshop and split this single image into 6 different images and then copy each of them to cubemap image or can just load entire image and copy it somehow?
Yes, that's possible. Vulkan doesn't know about formats like PNG and you're free to copy from your source to a Vulkan image. In your case you'd create a Vulkan image cubemap and then use e.g. vkCmdCopyBufferToImage to copy the cube map faces from a raw (RGBA) stb buffer to the appropriate face of that image.
