Since the other post was all about special attacks I decided to create a new post for this one. I have finally created a Snow Techtree and anim files for snowy maps.
I only tested in for the Norse Age 4 Houses for the time being. But it works.
There are 5 Main Technologies
Snow Main
Snow Age 1
Snow Age 2
Snow Age 3
Snow Age 4
I added Snow Age 4 to the House Anim file. If the Snow Age file is active, the roofs appear snowy. But it doesn't end there:
For each age there is a PERSISTENT tech that checks if Snow Main and Age 1 (or Age 2) are active at the same time.
If Snow Main and Age 2 are active at the same time, then the Snow Age 1 is activated.
So far it works perfectly.
One problem: The first code needs to be added manually to the map, or to the scenario using triggers or the RM code. Haven't tested that part yet, and that's the most important part.
This is the closest thing to a terrain logic I can create at the moment. The theory is solid, and all the Norse textures are already created. I just have to work hard to code the rest of the anim files.