Hollywood studios are already using game engines like Unreal to create virtual sets in real-time. I could see some sort of hobbyist pipeline being created that will get a decent starting point made.
Workflow would be like this:
>use GPT to generate scenes and ideas
>GPT then used to create multiple different scripts, human chooses the best for each scene
>AI voice synthesizer used to do the dialogue
>Stable diffusion or equivalent used to create multiple 3D models for characters, finishing touches by human
>models then used by game engine to act out the scene, not sure how much of this can be done via AI
>live action stuff can use deep fake technology with any random person being deep faked to look like the AI generated unique character
I can see some crazy animated/CGI movies being produced much cheaper than traditional Hollywood style used now. We could see indie projects with the look of much bigger budget projects thanks to automation. It will level the playing field somewhat and allow people with better ideas to flourish, rather than just people with connections to get funding from studios.