1. Choose how to fill the world
Use Place or Paint from your generator script when you want it to choose individual plant positions. Use painted Density or Noise for background grass that you prepare before Play. Plants added by the API belong to the Manual placement group, even though a script placed them.
2. Choose a plant type
Each entry in the Type Set is a type of plant, such as grass, a flower or a tree. Its typeIndex is its position in the list, starting at 0. Variants give that plant several possible sprites without turning it into a different plant type.
3. Decide where plants are allowed
Your generator can skip roads, water or buildings. Automatic Scene Mask can also block chosen sprites or colliders. The painted Placement Mask only hides plants; it does not stop their records from being added.
4. Use repeatable random choices
A seed is the starting number for random variation. Use a saved world seed and a number for each region when you want the same world to return after loading. Reuse the same positions, types and seeds to reproduce your placements.