Creating Rivers and Water Sounds

Your map may need rivers or streams linking different water bodies. We suggest using our built-in tools to accomplish this.

INFO

Rivers currently do not support being swimmable unless they are perfectly flat. If they are flat, you can assign a physics volume to their area which should make them swimmable.

Creating Rivers

Step 1 - Creating River Spline with River Tool

1. With your mod map open, go to Content/Blueprints/Water and select BP_WaterSpline
2. Drag the WaterSpline blueprint into your level.
3. You will see a small white dot on the river spline you just created. Select it and drag it around to lengthen your river.
4. Hold down ALT on your keyboard and drag the white dot to create a new spline node.
5. Create as many spline nodes as needed to create the length of your river. If you drag your node up or down, it will automatically create a waterfall.

TIP

• Create your river starting from source to end, that way the water will flow in the correct direction.
• You can change the width of the river by changing the XYZ scaling of the spline point.

Step 2 - Turning Spline into Mesh

Once you have created your river layout, we need to merge it into a static mesh so it can be drinkable by creatures.

1. To to Window > Developer Tools > Merge Actors to open the Merge Actors window.
2. Select your river spline, and Click "Merge Actors". This will turn your river spline into a fixed mesh. You cannot edit the river after completing this step, so ensure your river is correctly shaped before clicking "Merge Actors"
3. Save your newly created river mesh into your mod folder.

Step 3 - Create River Base Blueprint

1. Inside your mod folder, right click and select New Blueprint Class.
2. In the "Pick Parent Class" window, select "IWater" and click "Select" to create a new blueprint.
3. Name the new blueprint something descriptive, such as BP_MapName_RiverBase

4. Open the River blueprint and assign your river mesh to the StaticMesh section.
5. In the river blueprint, select "+Add Component" and add an ICreatorModeObject
6. Select the ICreatorModeObject and assign CMO_Water to the Creator Mode Data Asset.

Step 4 - Create Individual River Blueprints

1. Right click on your BP_MapName_RiverBase river blueprint and select Create Child Blueprint Class
2. Name your newly created blueprint BP_MapName_RiverName and ensure you save it into your mod folder.
3. Assign your river mesh to this blueprint. If you have created multiple river meshes, you should create multiple Child Blueprints and slot a mesh into each blueprint.
4. Drag your river mesh into your map. Position it exactly in the same place as the old Spline, then delete the spline. This will leave just 1 river mesh remaining.
5. Ensure your river blueprint is correctly assigned to its sublevel.
6. Additionally, ensure you assign a Water Tag to your river, as explained here in Step 3: Adding Tags to Water Bodies

Adding River Sounds

1. Go to Content/Blueprints/Water and drag BP_RiverAudioSpline into your level.
2. Select the small white spline point and drag it out along your river length.
3. Hold Alt on your keyboard and drag to create a new spline point.
4. When you are finished, it should look similar to the image below.
5. Ensure your river audio spline is correctly assigned to its sublevel.

Summary

In this tutorial you completed the following:

• Use the spline tool to create river splines.
• Converted the river splines into a mesh.
• Created a river blueprint and assigned the river mesh.
• Added river audio spline to your rivers