Please help me! I am thinking of generating different terrains environment every time the game loads again. But i am thinking of loading or drawing a image containing all the units like river, land and tree. Then the checking of obstacles against the units like boat, car and plane. I have done lots of research but i am struck on how to do it. Please help me.
The question is a bit general so here's a general answer. http://code.google.com/p/libgdx/wiki/TiledMaps gives a tutorial on using a tilemap (http://www.mapeditor.org/) within your game. You can dynamically change tiles, etc. Each tile may have properties, such as which objects are stored within it, or whether it is water (in which case you'd only let a player swim or use a boat, but not drive a car) or whether it's a tree (in which case you can't walk through it) etc. If you want a more specific answer you'll have to provide a more specific question.