> For the complete documentation index, see [llms.txt](https://docs.world-creator.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.world-creator.com/reference/terrain/biome/filters/basic-erosion/ridged-flows.md). # Ridged Flows ## **Overview** The Ridged Flows Erosion filter provides highly adjustable simulated erosion. The filter simulates water raining on the terrain, moving downhill according to the normal of the terrain, eroding and depositing sediment along the way. ## **Parameters**

Property	Description
Iterations	The number of iterations the simulation will run for. A higher iteration count will result in a stronger effect.
Viscosity	The viscosity with which the rain will run down the terrain.
Evaporation	The amount of water that is lost every iteration in each droplet.
Velocity Threshold	Eliminates rain droplets once their velocity becomes too low. The parameter is inverted, so 0 means no droplets will be eliminated.
Rain Strength	The amount of rain that is dropped at the start of the simulation.
Smoothness	Smooths the path of the individual rain droplets.
Flow Cutoff	Eliminates rain droplets once their water becomes too low. The parameter is inverted, so 0 means no droplets will be eliminated.
Flow Smoothness	Smooths the continuous flow of the rain droplets.
Sign	Changes a parameter in the flow direction computation.
Sample Size	Controls the sample area the flow direction computation uses.
Depth	Controls the depth of the erodible sediment. This influences erosion and sedimentation strength.
Erosion	A factor that affects the final amount of sediment eroded from the terrain. Any other value than 1 can disturb the equilibrium of the filter and add/remove matter from the terrain.
Sediment	A factor that affects the final amount of sediment deposited onto the terrain. Any other value than 1 can disturb the equilibrium of the filter and add/remove matter from the terrain.
Erosion Length Factor	Controls the smoothness of erosions. Lower values result in larger connected streams and higher values in more separated areas.
Sediment Length Factor	Controls the smoothness of sedimentation. Lower values result in smaller structures and higher values in more connected streams.
Start Resolution	Changes the map resolution the algorithm uses for its flow direction computation. A higher value might yield better results but can require more computational performance.

## **Results**

--- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.world-creator.com/reference/terrain/biome/filters/basic-erosion/ridged-flows.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.