Landmass and oceans

Now that I have my heightmap done, I have what I need to create a landmass and an ocean (or something equivalent, in case you're creating an extremely unique world). From past experience, creating the shape and size of the landmass and the oceans is actually a pretty difficult task. I tried doing it manually with varying results, and I also tried several photoshop variants, most of which were offered by the nice people at The cartographer's guild. And some techniques were brilliant. Few of those that produced good results were easy, however.

With my heightmap, every point in my map is a value between 0.0 and 1.0. By applying a filter, I can say that everything from 0.0 - 0.5 is ocean (black in the image shown), and everything from 0.5 - 1.0 is land (white).

1) The heightmap used

2) The result after the filter.

I like the result. It produces no visible artifacts, or any bias towards any specific direction.

This could hopefully be useful even for those of you who like to handcraft your maps. With that magic wand, you should easily be able to split land and ocean into two different layers in Photoshop.


  1. 1st, thanks to Tormod Aarlott Digre for mentioning this on G+.
    2nd, this looks very cool. I especially like the black and white land/water map above for a random map.

    I look forward to seeing the process develop further and hopefully with some simple instructions for a novice like me to create simple maps. Thanks.

  2. Hi,

    The ultimate goal is going to be an online generator, (or at least an automated tool of somekind), so that we all can create beautiful maps :-)

    I appreciate the interest, and welcome any questions or suggestions.