Hi xpez2000,
You could create productivity tools like you've described using Python or another programming language.
You could also use chatGPT as tool to help you understand and write certain parts of that code within the programing language of your choice. For example, I recently delved into the principles behind the math involved in a 4 x 4 matrix, an approach which Terragen uses when saving population caches in popxml format. ChatGPT help me understand the nuances involved and was like having an instructor available to answer my questions as they arose.
On my Windows desktop I have a couple of batch (.bat) files for batch rendering Terragen projects overnight. They are basically text files, so there's no reason that a productivity tool couldn't be written in Python, for example, to generate the batch files themselves.
Terragen 4 Professional now includes a Remote Procedure Call (RPC) feature which allows third party programs to communicate with the open Terragen project. A geo-mesh auto tiler application could probably be coded to do this, that is load and manipulate the position of said geo-mesh. I'm not sure about an FBX importer, but more to the point, you could definitely write a program that looks at the MTL file associated with an OBJ formatted object and write out a Terragen clip file with the image textures assigned to the proper inputs of a Default shader. The clip file could then be loaded into the internal node network of the OBJ within Terragen. I've done this sort of thing to "transfer" surface material settings from Daz 3D assets in OBJ format to Terragen, which can be a big timesaver if an OBJ has a lot of surfaces.
Be sure to take a look at the recent blogs we've posted about Terragen RPC here:
https://planetside.co.uk/blog/hello-rpc-part-1-scripting-for-terragen/https://planetside.co.uk/blog/hello-rpc-part-2-error-handling/