Terrain generation

Procedurally generated terrain is must-have if I want to claim that the majority of content is procedurally generated. Here we are making the first step toward that goal, and also it was my homework. Now I present to you, how I proceeded.

My assignment was to create a noise-based terrain generator and biomes, where each biome has different parameters. Originally I was supposed to work on provided Minecraft project, but I struggled with Java therefore I’ve eventually returned to Unity.

Noise

First, I needed to create basic terrain with fixed parameters. From the task, I was recommended to use Perlin noise, which is embedded in the Unity Mathf library. Then I applied it to Unity mesh. That was nothing new to me. The only thing that was a bit hard, was scaling properly the output mesh 4 times to get a larger space with the same computation cost. I struggled with vector transformations.

The results were not good enough. Therefore, the next step was to smooth it out. I applied octaves. They are additional layers of Perlin noises that are decreasing in amplitude (value) and increasing in frequency. Also to get a further variance, an extremely large random number is generated to offset each octave. The result of this process is a smooth texture as you can see in the image up top.

Octave math comes something like this:

for (int o = 0; o < settings.Octaves; o++)
{
    var perlin = Mathf.PerlinNoise(
        frequency * x + settings.OctaveOffsets[o].x,
        frequency * y + settings.OctaveOffsets[o].y
    );

    height += amplitude * perlin;
    amplitude *= settings.Persistance;
    frequency *= settings.Lacunarity;
}

To achieve universality, I needed to scale the result to receive a value from 0 to 1 at the end. Also, all scalings, offsets, and multiplications had to be parametrized to be changed dynamically later. Noice settings contained:

• level of octaves
• octave offsets
• seed for random generation of octave offsets
• range mapping of output
• offset of the output
• lacunarity = multiplicative coefficient for increasing the frequency in octave
• persistence = multiplicative coefficient for decreasing the amplitude

Next step

I prepared noise generation and now I need to create biomes. You can see them in the image up top as terrain color, but I will get more deeply into that topic in the next post.

Thank you for reading and if you want, buy me a coffee.