Thanks again for your reply,

1: I actually still don't really know what you mean. What is TUST? I really don't want to use some external libraries. You mean a dynamic model (generated by script?) which has vertexes and doesn't contain sprites?

2: Okay thanks for the multitexturing tip! Is there something like a good tutorial about multitexturing? I know the basics but I'm actually not a real pro in it.

Greetings, Simon

Edit: One more question to (2):
Is it also possible to do something with multitexture like this:

I mean the different ground textures perfectly fitting into each other. If yes, may you tell me how?

Thanks, Simon