River - Lumberyard User Guide


This feature is in preview release and is subject to change.

Use the River component to carve riverbeds into the terrain and fill them with moving water. The River component uses 2D materials to create the illusion of flowing water. Optimally, you should use this component to create flat rivers along level terrain. To create rivers that run downhill, you can create a series of rivers separated by occasional waterfalls.

The River component requires the Spline component to shape its path along the x, y, and z axes. After you place a river, you can edit the points in the river's spline.

To use the River component, you must enable the Roads and Rivers gem. For more information, see Enabling Gems.

            Example animation of the River component.

River Properties

                River component properties.

See the following River component properties.

Name Description
Global width Sets the width of the river.
Per-Vertex Width Modifiers Modifies the width at a specific vertex that is added to or subtracted from the Global width. For more information, see Modifying the River Width.
Elements The river's vertices or points. Specify a positive or negative value for each vertex.
Segment length Length of each segment. Smaller segment lengths increase the polycount used for the river curvature. To create a river with smooth corners, specify lower values.
Tile length Length of the river texture. Adjust this parameter with Segment Length to avoid stretching textures.
Sort priority Priority that you can set if the river intersects with another river.
View distance multiplier Distance at which the river is visible. The default value is 1. A higher value indicates a longer visibility distance.
Minimum spec Specifies the minimum system configuration level for the effect. If the configuration is lower than the set value, the river will not appear. Choose from Low, Medium, High, VeryHigh, and Never.

Default value: Low

Tile width Width of the river texture.
Depth Depth of the river.
River material Material file for the river. For more information, see Setting River Material Properties.
Cap at Depth

If selected, limit fog rendering to the river's bottom.

If deselected, fog continues to render below the specified depth of the river.

Density Specifies how dense the fog appears. Specify higher values for thicker fog.
Color Color of the fog.
Affected by Sun If selected, the value for the Sun color parameter in the Time of Day Editor affects fog color of the river.

Sets the shadow darkness on the surface of the river.

To enable this parameter, set the console variable r_FogShadowsWater to 1. For more information, see Using the Console Window.

Caustics - Enabled Enables caustics – Light rays that are reflected or refracted by the water's surface.
Intensity Intensity of normals during caustics generation.
Height Distance above water's surface that caustics are visible.
Tiling Tiling of normals during caustic generation.
Physics - Enabled Bind river with CryPhysics.
Speed Defines how fast physicalized objects are moved along the river. Negative values move objects in the opposite direction.
Border width Specifies the width of the slope on the borders of the river.
Embankment height Defines the height of the slopes on the borders of the river. If the river is at ground level, specify an embankment height to make the river appear to flow.
Depth of the river bed Defines the depth of the ditch beneath the river.
River bed width offset Defines the width of the riverbed relative to the river's width. A value of 0 makes the riverbed the same width as the river. A value of -1 makes the riverbed one meter narrower, and so on.
Erase width

Distance from the river edges in which the vegetation should be removed. Set the parameter to 0 to remove only vegetation that is on the river. Specify positive values to remove vegetation in a wider border from the river's edge. Specify negative values to leave some vegetation within the borders of the river.

For more information, see Erasing River Vegetation.

Erase variance Randomizes the removal of vegetation so that the edge looks more natural.