How do I check what sprites are touching what?

Hi

I am creating a top down earth layout using tiles of 32x32 individual sprites. I need a way to test what sprite is next to what then be able to change it. Eg - If sand is next to water at a set point (high tide) change the sand closest to the water to water tiles. Any ideas - tried everything?? Thanks

Put the objects into a family and the use the pick closest or on overlap at an offset. Then wright your conditions for each type of object that it has to change for.

Hi,

Here's two tutorials about how to achieve this. This is the bitwise method. A little bit difficult to implement but works like a charm.

http://www.saltgames.com/2010/a-bitwise-method-for-applying-tilemaps/

https://www.scirra.com/tutorials/746/auto-tile-using-sprites-arrays-and-a-bitwise-method

https://www.scirra.com/tutorials/1128/auto-tiling-with-autotilegen-and-tilemaps