Are there any softwares that you can import pictures into, and edit having it show you how the pictures will form as a skybox. Sorry for the phrasing, but I want a visualization instead of just photoshopping pictures back and forth so they blend together, but a lot of time is wasted there.
To expand on what SpikeX said, Unity will work almost as you described. If you have any kind of Asset in Unity's Asset directory, and change it - Unity will update it in realtime. Unity is constantly checking the Assets directory for any changed files, and it re-imports them.
So what you would do:
- put six Photoshop .PSD files into Assets, and Make a Skybox out of them.
- Alt-tab from Unity to Photoshop (or whatever program), edit the files, and save them back.
- Alt-tab back into Unity, and it will automagically update them, and your Skybox will have changed, so you can see it without re-importing.
- Expand the Game window and Run it, and you'll be able to rotate around (assuming you have a Controller) and see the whole Skybox. (or as SpikeX said, check the skybox option in the Scene window to see it there).
This may not be the same as editing and viewing the images in the same program, but it only requires alt-tabbing between two programs, so it's close. Let me know if you have any questions about it.