Rivers
Last updated
Last updated
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The Rivers shape layer offers you a highly advanced river building toolset with multiple realistic auto generation options as well as a plethora of tools to individually customize a river to your exact liking.
The river system gives you several different ways, which are presented below, to build your network. In general, it is designed to allow you to create a complete procedural river network as quickly and easily as possible, giving you a starting point for then creating the perfect river layout for your terrain with precise control over every aspect of the result.
Ideally you will want to start with the Auto Generate/Build from Spring approach as both of these will create brand new river networks. The Generate Stream functionality, on the other hand, can be very useful when modifying an existing network, as it works well within your current river network.
Automatic generation is the easiest way to get a river network for your terrain. To do this, press the Rebuild Rivers button in the generator settings. World Creator will then automatically analyze your terrain, calculate flow paths, place and connect springs and river nodes and assign different river types according to the hydrological properties sampled at the determined locations.
To then further refine your river network, press the Edit button at the bottom of the panel to gain full control over every aspect of the generated system.
Bear in mind that this mode will create a completely new system, so any changes you've made to the river network will be overwritten.
This approach gives you full control over where the rivers start as you only have to place the springs and let World Creator handle the river generation downstream from there. To add a spring, simply press Shift & LMB in the Edit mode.
You now have two options:
Build From Springs This works in a similar way to Auto Generate and will create a completely new river network based on your springs, i.e. everything other than the springs in the layer will be overwritten.
Generate Stream This will only create a river from the currently selected spring. It works within an existing river network, so all other rivers will be left untouched and the newly created river will flow into an existing river if it encounters one.
Besides the procedural generators World Creator offers you also have the option to fully construct your own graph. To add a new node enter the Edit mode and press Shift + Lmb. With Shift + Drag from the new node you can now place a new node connected to the original which allows you to build up your network. Additionally you can also fuse nodes together by using Ctrl + Drag and dropping it on another node.
World Creators River Layer offers a complex river network system with several core design concepts as its foundation. Understanding these is highly recommended to unlock the system's full potential.
Each River Node can be one of the river types listed below. The automatic determination of River Types is based on the expected throughput of water and the slope of the terrain at a node's location. The River Types are inspired by the different Rosgen Types used in the geological stream classification and affect:
Course of the river - straighter and faster flowing or more meandering
Cross-section - V-shaped entrenched or smoother, wider profile
Stream Count - Braided or Multi-Threaded River Types are made up of several individual channels
Rendering Multipliers - Each River Type internally influences the different rendering multipliers to create, for example a flood-prone area or wider valleys around the stream.
Mountain Steep Rosgen Type Aa+ Usually placed on steep slopes, fast straight streams with a V-shaped cross-section.
Mountain Rosgen Type A A slower flowing version than Mountain Steep => less aggressive cross-section and wider stream course.
Gently Sloped Rosgen Type B Most often found on the side slopes of valleys with a softer and wider profile.
Valley Rosgen Type C More sinuous stream, found predominantly in wider valleys with a soft cross-section.
Braided Rosgent Type D Shallow multi-channel stream found in valleys.
Multi Threaded Rosgen Type DA Shallow multi-channel stream with more diverse individual channels.
Floodplain Rosgen Type E A typical narrow floodplain stream with a high meander ratio that is mostly found in valleys.
Meandering Rosgen Type F Wide meandering river found in flatter areas with a steady and slow flow.
Flat Rosgen Type G Narrow and deep stream with a V-shaped cross-section.
Flow describes the volume of water at each River Node and affects the width, sinuosity and depth of the river. The flow value is calculated by adding up all incoming flows of a node's parent nodes.
There are several ways to control the flow at a particular node:
Increase the flow of the base spring or any node above the wanted node.
Adjust the flow multiplier at the given node to increase its flow relative to the inflow.
Activate Set Flow and manually override the current flow value of the node. Note that this will break the link between the flow of upstream nodes and this node. Nodes further downstream will be affected by the new flow value.
Valleys are structured around the stream, providing a base for the stream to flow into and controlling the blend between the stream itself and the terrain. By default, they work on the lower levels of the level-step system to blend in with the terrain.
The valley is divided into two parts:
The floodplain that surrounds the possibly meandering stream and provides a base for the river to flow through.
The valley, which lies outside the floodplain and blends into the original terrain, with additional options for additional noise and control over the shape of the transition.
Adjust Upstream Nodes
(SHIFT)
Select Node
Left Mouse
Move Node
(SHIFT) + Left Mouse + Drag
Rotate Node
(SHIFT) + R + Left Mouse + Drag
Adjust Node Height
(SHIFT) + ALT + Left Mouse + Drag
Remove Node
(SHIFT) + CTRL + Right Mouse
Add Spring
SHIFT + Left Mouse
Add Connected Node
SHIFT + CTRL + Left Mouse + Drag
Use Global Sea Level Links the internal sea level of the layer to the global sea level used for ocean rendering.
Sea Level The height at which the generator ends new rivers.
Branching Increases the number of crossings and branches the generated river network will have.
Max Lake Depth The river ends when the generator reaches a point where no lower neighbouring cells exist, creating a local depression that would form a lake with the minimum given height.
Slope Multiplier Multiplies the slope values at each node, which affect the automatically determined river types at each node. For a standard terrain, a value of 1 should work best. Adjust this if you are going for more extreme, steeper terrains.
Min Flow The minimum flow each node has. Increase this to get stronger rivers overall. This also changes the automatically determined river types.
River Type Smoothing Assimilates river types between intersections to create a more unified and coherent river.
Seed The river layers global seed.
These settings affect all streams of the river network and are mainly global multipliers for the parameters found in each node.
Depth Alters the depth of all streams.
Width Changes the width of all streams.
Curve Amplitude Allows you to increase/decrease the strength of the curve effect applied to the stream, which can create more/less widely meandering rivers.
Curve Repetition The scaling of the curve function that runs along the river streams.
Levels The strength of the stream carving on each level step.
These settings affect the valleys surrounding the streams, ensuring a smooth integration of the streams into the terrain. They are split into a floodplain area where the river stream can meander and a blending area that slowly fades into the terrain.
Width Multiplier for the width of all valleys.
Depth Shifts all valleys downwards.
Wall Shape The steepness of the blending between floodplains and terrain.
Breakup Adds additional noise into the blending region between floodplains and regular terrain.
Floodplain Controls the width of the floodplain area.
Floodplain Flatness Controls the flatness of the floodplain.
Levels The strength of the valleys on each level step.
Export Spline Exports all streams as a spline in a .dae file.
These parameters become available once you press Edit at the bottom of the River Layer panel, allowing you to adjust your rivers in more detail on a node-by-node basis.
Clear Springs Removes all nodes (springs & regular nodes) from the current river network.
Build From Springs Recomputes the river network from all given springs in the current river layer and builds their downstream stream network.
Seed The seed of the current river node.
Set Flow (only available on non-spring nodes) Toggles between the Flow Multiplier value (relative to the upstream parent node) and the Flow value (absolute flow value).
Flow Multiplier (only available on non-spring nodes) Takes the parent node's flow value and multiplies it by this modifier to create the current node's flow value.
Flow The absolute flow value of this node.
Custom River Type Lets you change the current node's automatically determined river type.
River Width Multiplier for the width of the riverbed.
River Depth Multiplier for the depth of the riverbed.
Floodplain Multiplier for the width of the current node's floodplain.
Valley Width Multiplier for the width of the surrounding valley.
Walls Multiplier for the wall steepness of the valley blending.
Channel Count (only available for River Type Braided and Multi-Threaded) Number of stream channels.
Curve Amplitude Increases/Decreases the curve amplitude for this node.
Curve Repetition Increases/Decreases the curve repetition for this node.
