I make a map by 。X file，and no textures with it ，
firstly i divided the map in to the squares，
and i want add the textures in the runtime，and i can
apply textures to a specified squares，
for examples I want some squares using textureA，and some squares using textureB，and others using textureC，
but i find no examples for it ,and i can not find the functions ,
how can i do it ，can someone help me?