Second, there are over 10 different terrain types and this affects movement speed, defense, spotting, etc. Third, the world is rendered as a series of polygons with bitmaps laid on top. The world is contoured so mountains go up and obscure vehicles behind it. A. Raw materials include lumber, coal, iron, oil, and xilitium. Coal and Iron go to the smelter to make steel.
Oil goes to the refinery to make gas.
Food and gas are global but all other minerals remain local. Steel must be transported from the smelter to the weapons factories. In other words, take out someone's supply line or critical building and you can really hurt them Losses to the economy slow things down. If you run out of gas all your vehicles slow down - but still run. If you are low on power buildings produce slower with buildings like farms being slightly affected and weapons factories brought to a virtual standstill.