Rivers

Rivers are special kind of splines used specifically for creating rivers.

Unlike tracks and roads, they do not have a thickness but they aren't like decals.

To simulate the water flow, with moving foam, rivers have special shaders that can be activated using some special parameters of the river material.

To know about how to create a river material see Creating a river material tutorial.

As example there is a ready to use river material in the nature base pack into the "roads" folder:

To access the rivers panel click on rivers tab in the splines tool panel.

River editing

In this section you can edit points of an already create river.

To create a new river see Rivers list below.

The buttons on this section are radio buttons, this means that a button remains pressed until you click on another button on the toolbar.

Add a new river point

When this button is pressed, every time you press left mouse button on a point of the terrain a new river button is added following the previous one.

If you hold the left mouse button when adding the new point, you can move it on the terrain until you reach the desired position.

The last point of the river is the one you cannot move. If you click on it a new point will be created and moved.

Do not forget to select a river before adding new points.

If you click on an already created point you can simply move it on the terrain as described before.

You can also add a new point between two points already created:
Move river point

When this button is pressed you can only select and move a point on the river.

You can move it in two ways:
Sliding on the terrain: As described when adding a new point, select the point a hold left mouse button while moving.
Use gizmos: You can use the point gizmo for moving along one axis separately.

You can move also the up axis gizmo for placing the river point at a certain distance from the terrain surface.
As described below you can then adapt the terrain to the river
Delete selected river point

This is the only button that, if pressed, doesn't work as radio.

If you want to delete a river point simply:
select the point
click on delete button

Here is where you can create a new river or select / delete an already created river.

To create a new river:

Click on button to add a new slot to the list
Select the newly created <empty> slot and click on button.
Choose the material you want to assign to the river from the appearing material browser dialog.

To delete an already created river:

To select a river click on the related row into the list.

The selected river will be showed with an azure wireframe in the scene viewport.

The river points are showed as azure boxes in the middle of the river section.

When you select a river point it becomes yellow.

In the case of the river spline, terrain adapting is useful for creating the river channel on the terrain surface.

In this way it will be possible to place the river surface on top of the channel giving a depth to the river water.

To do this:

As in the case of tracks and roads, set the width of the channel using the width parameter,
Set the depth parameter to determine how much deep the river must be.
After chosen the width and the depth of the river channel you can click on Adapth Terrain To River button for creating it.
Then you can adjust the bias and the width of the river (see river parameters) in order to make it to fit in the channel.

River Width

The width of the river in centimeters. It is useful also for fitting the river surface into the river channel.
River Max Dist

The maximum distance at which the river can be drawed (in centimeters). It is used for optimization purpouse.
River Bias

This parameter is used for vertically moving the river surface.

This is useful for best placing the river surface on the river channel on terrain created when using the terrain adapting algorithm.