Is there any demo source code for digital twins that can refer to for learning

I am developing a digital twin project for highways and have encountered some tricky issues, such as color matching, terrain, mountain maps, and dynamic creation of tunnels and roads. I wonder if there are similar demos that can be referenced and learned, which can provide some inspiration for better and faster project development

I do not think I have seen any of them being Open Source.

I think the easiest way to help you is to explain the individual problems separately and create a small demo in the playground.