Asset Link: https://assetstore.unity.com/packages/tools/utilities/quick-level-generator-171132
2 types of generators included
1. Texture to level: Generates prefabs in place of pixels. Colors of the pixels are carried down to the prefabs. Optimizes material generation by reusing materials. Materials are exported into a folder. Further optimization can be done by reducing “Quality” which reuses materials and does a lossy generation
2. Mesh to level: Generates prefabs in place of vertices. This means that prefabs amount will be equal to amount of vertices. Use with caution. A color gradient can be used to generate color on the generated level. It does not use color from texture of the mesh.