Working with the River Component - Lumberyard User Guide

Working with the River Component

See the following procedures to create a river and modify its appearance.

Creating a River

To create a realistic river, use the River component's Carve River Bed tool to prepare the surrounding terrain. This tool carves out a riverbed and creates riverbanks on the edges of the river that are higher than the river's water level.

You can also paint the river bottom with a different texture than the surrounding area. This is useful if the water has translucent properties. For more information on painting the terrain, see Painting Terrain Texture Layers.

To create a river

  1. Create an entity.

  2. Add the River component.

  3. Add the Spline component.

    The Spline component defines the path and shape of the river. For information about how to add, remove, and edit individual points, see the Spline component.

  4. Under Terrain Editing, specify values for the following parameters:

    • Border width – Sets the width of the slope on the river's sides.

    • Embankment height – Defines the height of the hills on the river edges. If the river is at ground level, this parameter makes the river appear to flow in the riverbed.

    • Depth of the river bed – Defines the depth of riverbed.

    • Riverbed width offset – Defines the width of the riverbed in relation to the river's width. For example, a value of 0 makes the riverbed the same width as the river; -1 makes the riverbed one meter narrower than the river; 1 makes the riverbed one meter wider than the river.

  5. Click Carve River Bed.


A river on the ground before a riverbed has been carved out.

                        River on the ground before carving a riverbed.

A river with a Border width of 5.0, Embankment of 1.0, Depth of 2.0, and River bed offset of -1.

                        Example river with a smaller embankment and border width.

A river with a Border width of 10.0, Embankment of 3.0, Depth of 2.0, and River bed offset of -1.

                        Example river with a larger border width and embankment.

You can also lower the river below the ground level and carve the riverbed. This achieves a different type of terrain deformation.

A river with a Border width of 10.0, Embankment of 1.0, Depth of 2.0, and River bed offset of -1. This river is positioned below ground level.

                        Example river that is below ground level.

Modifying the River Width

You can use the Global width parameter to adjust the river's width. This parameter modifies all the points on the river.

For more refined control over the river's width, you can adjust the individual points with the Per-Vertex Width Modifiers parameter.

                    Per-Vertex Width Modifications with four

To adjust the width of individual points

  • In the River component, specify a negative or positive number for the element that you want to modify.

    Negative numbers subtract from the Global Width parameter, while positive numbers add to it. A value of 0 means that point is at global width.


    The global width of this river is 2, and the width at the selected point is set to 5. That means the total width at the selected point is 7.

                                River with one vertex widened

Erasing River Vegetation

You can erase vegetation around the river's borders.

To erase vegetation

  1. In the River component, for Vegetation Editing, set the Erase width. This defines the amount of vegetation to erase at the river's edges.

  2. Set the Erase variance. This parameter randomizes the removal of vegetation so that the edge looks more natural.

Setting River Material Properties

The road material must use the WaterVolume Shader.

To set the river material

  1. Press M or navigate to Tools, Material Editor

  2. Select the defaultRiver or other appropriate river material.

                    WaterVolume Shader parameters

For information about the WaterVolume Shader properties, see WaterVolume Shader.