Note,This is a cross post at androidpit.com,sine I have not got any attention there after two days,so I post here. =================================== We want to build a lbs app like google map in android. Since we have our own map source data. Then we meet some problems which make we can not start the developement. Since we use the map tiles(create the images with 256x256px and load them accordingly) in the PC. But the tiles take too many space which is not suitable for mobile device. Then we want to display the map based on vector data(google have implement this). Now we do not know how to draw vector object in android. In fact we just need to draw points,lines and polygons. Also we want to implement the 3d view like google map if possible. Then any ideas? Any useable library or something else? BTW,we also want to create a similar app on IOS,so we appreciate if we can build a common re-useable library(maybe use c),the we buitild our app based on this library (it seems that the andorid ndk support call native .so library in java isn't it?) Is this possible?