So, the reason why plates didn't match when loading a heightmap is because a heightmap contains barely a fraction of information needed to reconstruct a detailed platemap. As such, Gleba doesn't even try to do that. When you import heightmaps, only climate data will be generated. Everything else will be populated with random placeholders.
There's basically three, mutually exclusive workflows here:
- don't import any maps, generate a fully random map, meant for people without a good idea of what world they want yet
- import a crustmap and/or platemap, itll generate a full world using those crust and plate layouts, best used when you have a general idea of what you want but you don't want to spend time creating all the detail by hand
- import a heightmap and get only climate data as a usable output, useful for people who have a finished world and just want to double check the climate zones
Since you mention trying to simulate Earth and projecting what it may look like in the far future - I thought it may be worth clarifying that Gleba isn't the right tool for it. We don't offer any tools for manually advecting plates either into the future or into the past.
That being said, forecasting Earth into the future isn't that uncommon so you may be able to use other people's work. Here's some wikipedia articles with different forecasts for the future of Earth (see sources for actual papers):
https://en.wikipedia.org/wiki/Pangaea_Proxima
https://en.wikipedia.org/wiki/Amasia_(supercontinent)