Heightfield Erode v3

Heightfield Erode v3

Overview

Heightfield Erode simulates the natural effects of weather and water flow on the terrain over a period of time. It enhances the realism of a heightfield by creating gorges, chasms and redistribution of the surface material.

Settings:

• Name: This setting allows you to apply a descriptive name to the Erode node, which can be helpful when using multiple erosion processes on a heightfield.

• Result mode: This menu has two options.

Result mode options.

Erode Heightfield: This option erodes the terrain based on the various settings below.

Difference (Erosion Field): This option returns the difference between the calculated erosion process and the original heightfield it was generated from. Once saved via a Heightfield Generate node (see image below) as a TER or EXR file, it can be merged with the original Heightfield allowing the amount of erosion to be increased or decreased or even animated.

Difference (Erosion Field) Flow distance = 100	Difference (Erosion Field) Flow distance = 1000
Node network pane. How to save eroded heightfield.	Node network pane. How to merge original heightfield and eroded heightfield.

• Flow distance: This setting controls the overall length of a channel or groove that is eroded.

Heightfield erode off.

Flow distance = 100.

Flow distance = 1000.

• Duration: This setting represents time. The higher the value the more time elapses, therefore more erosion and channels are created and the more time they have to interact with each other.

Flow distance = 100, Duration 0.25	Flow distance = 100, Duration = 1 (default)	Flow distance = 100, Duration = 10
Flow distance = 1000, Duration = 0.25	Flow distance = 1000, Duration = 1 (default)	Flow distance = 1000, Duration = 10

• Erosion power: This setting controls how deep a channel or groove is. A value of 1 represents the highest possible erosion that could occur over the “Duration” value, or a given period of time.

Flow distance = 100, Erosion power = 0.25 (default)	Flow distance = 100, Erosion power = 1
Flow distance = 1000, Erosion power = 0.25 (default)	Flow distance = 1000, Erosion power = 1

• Deposition: This setting controls how much of the eroded material is deposited along the flow channel. A value of 1 is the most accurate, meaning that all of the eroded material is deposited along the flow channel.

Flow distance = 100, Deposition = 0	Flow distance = 100, Deposition = 0.25	Flow distance = 100, Deposition = 1 (default)
Flow distance = 1000, Deposition = 0	Flow distance = 1000, Deposition = 0.25	Flow distance = 1000, Deposition = 1 (default)

• Deposition rate: This setting controls whether the redistribution of eroded material along the flow channel is biased towards the beginning or end of the flow channel.

Flow distance = 100, Deposition rate = 0	Flow distance = 100, Deposition rate = 0.25
Flow distance = 100, Deposition rate = 1 (default)	Flow distance = 100, Deposition rate = 10
Flow distance = 1000, Deposition rate = 0	Flow distance = 1000, Deposition rate = 0.25
Flow distance = 1000, Deposition rate = 1 (default)	Flow distance = 1000, Deposition rate = 10

• Diffusion: This setting adds some random variation to the flow directions, which can simulate roughness in the terrain, as if the flow channels interact with each other.

Flow distance = 100, Diffusion = 0	Flow distance = 100, Diffusion = 1.5
Flow distance = 100, Diffusion = 3 (default)	Flow distance = 100, Diffusion = 10
Flow distance = 1000, Diffusion = 0	Flow distance = 1000, Diffusion = 1.5
Flow distance = 1000, Diffusion = 3 (default)	Flow distance = 1000, Diffusion = 10

• Diffusion adapts to slope: When enabled the erosion process will follow more closely the contours of the terrain.

Flow distance = 100, Diffusion adapts to slope off.	Flow distance = 100, Diffusion adapts to slope on.
Flow distance = 1000, Diffusion adapts to slope off.	Flow distance = 1000, Diffusion adapts to slope on.

• Slip at angle: This setting controls the angle at which the terrain begins to slip. A value of 90 degrees is the same as the setting being unchecked or off. Lower values allow steep slopes to erode quickly while higher values preserve them.

Flow distance = 100, Slip at angle = 15 degrees	Flow distance = 100, Slip at angle = 45 degrees (default)	Flow distance = 100, Slip at angle = 90 degrees
Flow distance = 1000, Slip at angle = 15 degrees	Flow distance = 1000, Slip at angle = 45 degrees (default)	Flow distance = 1000, Slip at angle = 90 degrees

• Auto calculate: When checked, or enabled, changes made to the heighfield settings will automatically cause the erosion calculations to begin.

• Erode Now: Clicking this button starts the calculations for the erosion process.

Legacy examples

Flow distance effect	Duration effect	Erode power effect
Deposition effect	Deposition rate effect	Diffusion effect

A heightmap or heightfield is an array of height values, usually in a grid which describe the height at specific points in a defined area. Heightfields are used to represent real-world and virtual terrain in a specific, easily converted format. Most heightfields can be represented as simple image data in grayscale, with black being minimum height and white being maximum height.

A single object or device in the node network which generates or modifies data and may accept input data or create output data or both, depending on its function. Nodes usually have their own settings which control the data they create or how they modify data passing through them. Nodes are connected together in a network to perform work in a network-based user interface. In Terragen 2 nodes are connected together to describe a scene.