Another Day (Blog Post) Another Dollar (No Dollar)

My apologies to Tom Siddell for stealing your joke for my post title.

Sorry to say there's yet again nothing to show this week. I seem to be in a bit of a rut. I think it'd probably be a good idea for me to set aside large-scale terrain generation for a while so I can make some progress.

I honestly can't really think of anything else to write about at the moment. I might update this post if I get an idea later today, but no promises.

It's a Small World After All

I'm still working on large-scale terrain. I decided to try a hexagonal grid rather than a square one because it seemed more natural. Plus, it avoided the awkward question of whether or not I should have water flow diagonally. Here's a screenshot. The terrain itself looks more natural, but lakes and rivers no longer form quite as easily, which I have to work on.

Here's a screenshot showing the hexagonal cells. Each vertex is one cell. The lines show the connections between them.

One thing that's changed is that the different layers can now mix together to a degree. I'm not sure if this was a good move. It's more realistic in some ways, but the results aren't quite as interesting. Feels like two steps forward and one step back. There are still a lot of things I want to add (temperature, humidity, snow and ice, plants, etc), but I'm trying to get the parts I have now working as well as possible before adding more complexity.

Interesting fact: the area I'm simulating is roughly four square kilometers, but this can be scaled up.

Building a Legacy

No update this week. I hit a bit of a wall on the project. Then I bought Rogue Legacy and kinda got sucked into that for a few days. I'll try to have something more next week!

Large Scale Terrain Generation

This week I worked on large scale terrain generation. The plan is run an environment simulation for some amount of time to create large scale structures (such as lakes, rivers, and mountains). The actual game will then use the large scale features as a guide for more detailed generation.

I'm using a different algorithm to generate the elevation. Specifically, I'm using the idea described on this page. I like this algorithm a lot because it's very simple and produces good results. Compare a planet created with Perlin noise vs. the spherical landscape algorithm:

Using Perlin noise.

Using spherical landscape.

Perlin noise tends to be more uniform resulting in a planet covered in lakes. While this can be overcome by adding multiple noise layers together, there are a lot more variables that need adjusting to get it looking good. With the spherical landscape algorithm, on the other hand, you need only to adjust the number of iterations. It tends to produce more varied results, which look more like oceans and continents.

Currently, the environment simulation works by iterating on several layers of 'fluid'. I use this term loosely because what I'm doing is not at all physically accurate (and I'm applying it to soil and sand in addition to water). The bottom-most layer is rock. Rock doesn't flow at all, but it can be eroded, which results in sand. Sand resists flow more than water, and soil more than sand, which creates flat-lands and beaches. Rain is simulated by evaporating water from every point and redistributing it equally.

The environment simulation is pretty bare bones at the moment, but it's already producing good results. I'll probably continue working to make it better for a few weeks before using it to generate actual game terrain.