# 2D side-scroller game : smooth noise transition between biomes

I'm creating a little terraria-like 2D side-scroller game with TypeScript. Currently, I divide parts of the world into biomes, which each have their own properties (flat, mountainous terrain, etc.). I am using a one dimensional Perlin noise to generate the height of the terrain for each biome. Currently this is a problem for me because the borders between biomes are not at the same height. How could I make the transitions between biomes smoother?

• Does this answer your question? How to blend biomes with procedural terrain Jun 28 at 10:27
• I'm not sure ... technically speaking, I'd like to know if it's possible to locally add octaves to a perlin noise? it could allows to have height variations per biome in a single perlin noise which would be smooth. Jun 28 at 12:35

• @Ekkaia You want a function that keeps the weight high for the most part of the biome, but has a fall-off on the edges. I used sin(b*π)² in my example, where b is current position in the biome, value ranging between 0.0 to 1.0. This requires to know the real bounds of the biome though. If that's unknown, you'll have to rely on very smooth / low frequency noise, e.g. perlin(x * 0.01). Jul 1 at 22:36