Hi On my little game (or I hope it will become one someday...) I want to use 2 different textures for the landscape: one for grass and one for mud. I want a smooth change between the grass and mud. I think the way of doing this is to draw a polygon with a gradually transparency filled with the mud texture over a polygon filled with the grass texture. My Problem is, that the distance between those 2 polygons have to be really big (if not you see just the grass texture or a ugly mixture of those 2). If the polygons are far away the mud-texture disappears. If I turn of GL_DEPTH_TEST it looks how it should be (but not the polygons of course...) here you can see how it should look: http://www.konstantin-schauwecker.de/secure/mud_grass.jpg

take a look at this:

http://www.cbloom.com/3d/techdocs/splatting.txt