WoLD Archives Search About Contact

World of Level Design

Tutorials to Becoming the Best Level Designer and Game Environment Artist (since 2008)

UE4: Complete Guide to Using Non-Destructive Landscape Layers - Splines

Category: UE4
March 03, 2020

"The best thing about Landscape Layer Splines is when you modify the Spline's Control Points and Segments - landscape updates in real-time which didn't happen before, prior to 4.24+."

Landscape Splines allow you to create linear features such as roads, railroads and pathways that will conform and modify the terrain underneath it.

Landscape Splines have been in UE4 for some time but now with addition of Landscape Layers in 4.24+, using Splines became a lot easier to use.

Make sure you've gone through the 2 previous tutorials that cover how to use Landscape Layers for Sculpting and Texture Painting:

In this tutorial I'll focus entirely on how to use Splines with Landscape Layers. I won't cover how to use Splines very much because that was covered in-detail in "UE4 Landscape Essentials" tutorial course (video 01.16).

Let's begin...

Video Tutorial: Landscape Layers - Splines (4.24+)

Enable Edit Layers to Use Reserved for Splines

To use Splines with Landscape Layers you have to Enable Layers on the landscape.

2 ways to Enable Edit Layers on your landscape:

  • During the creation of a new landscape
  • In Details panel for existing landscapes

Creating Landscape Splines

To add Splines to your landscape go to Landscape Mode > Manage and choose Edit Splines:

In the Perspective Viewport, Hold Ctrl and Left Mouse Click to insert a Spline Control Point:

Hold Ctrl and Left Mouse Click again to create another control point. Continue to Hold Ctrl + Left Mouse Click to place additional Spline Control Points creating a linear path:

Landscape heightmap won't change at the moment. Just focus on creating the Spline pathway for now.

Keep Use Auto Rotate Control Points enabled, this helps to orient your Control Points as you place them:

What is "Deform Landscape Splines" Option

Within Manage > Edit Splines you have "Deform Landscape to Splines" option for "All Splines" or "Only Selected":

Do not use Deform Landscape Splines option. This ONLY applies if you are NOT using Landscape Layers.

If you "Deform Landscape to Splines" prior to creating a Landscape Layer for Splines then whatever Landscape Layer you have selected will be modified. The changes will be applied to that selected layer. Not something you want to do unless you are NOT going to be using Landscape Layers.

Adding Splines to a Landscape Layer (Reserve for Splines)

To add a created Spline to a landscape Layer you have 2 options:

  • Create a new Landscape Layer
  • Use an existing Landscape Layer

Right-Click on a Layer and choose Reserve for Splines:

When this menu pops up: "Reserving layer Layer1 for landscape splines will clear it from its content and no edition will be allowed. Continue?"

Choose Yes:

All existing Splines will be assigned to that Landscape Layer, whether you had any Splines selected or not. Landscape heightmap will be modified automatically to those Splines:

All Splines will now be contained in one Layer and only Spline information can be edited within that Layer. Any new, additional Splines you create will be placed onto Reserved for Splines Landscape Layer.

The best thing about Landscape Layer Splines is when you modify the Spline's Control Points, landscape heightmap updates in real-time which didn't happen before, prior to 4.24+.

Only One Reserved for Splines Layer is Allowed

You are allowed to have only ONE Landscape Layer that is Reserved for Splines. If you decide to create a new Landscape Layer or use an existing layer then set that Layer to Reserve for Splines - any Landscape Layer that was set to Reserve for Splines will become a regular Layer and all the Splines will be moved onto a new Reserve for Splines layer.

Use Game Mode to See Landscape Splines Results

Press G to toggle Game Mode. This will allow you to see the modified Spline results in the landscape better:

Control Points vs Segments

It is important to understand the difference between a Spline Control Point and a Spline Segment.

Control Point: control elements for a Segment:

Segment: a section between two Control Points:

Editing Splines and the Landscape

If you go back to Sculpt Mode and select a Landscape Layer that is Reserve for Splines you can't do anything to it. Other than adjust the Alpha value or work with the Landscape Layer itself.

You must be in Landscape > Manage > Edit Spline Tool to place, select, edit, move or delete Spline Control Points and Segments:

Left-Click on a Control Point to select it and use Spacebar to cycle to Rotate or Move. Then move or rotate that Control Points to modify the heightmap of the landscape to the spline - automatically:

Switch over to Details tab where you can adjust properties for selected Control Points and Segments. Everything you change here will be updated in real-time:

Left Click to select a Spline Control Point then under Details Panel you can "Select All Connected: Control Points or Segments:

Selected Control Points or Segments will have different settings. It is important to know what you have selected and what you want to modify.

With Control Points you can set:

  • Width
  • Side Falloff
  • Left and Right Side Layer Falloff Factor (used for Texture Layers)
  • End Falloff of the Spline

With Segments you can:

  • Assign a Landscape Texture Layer to apply to the Spline
  • Assign Static Meshes
  • Adjust if you want to Lower Terrain, Raise Terrain or Both

Spline Layer Order Matters

Moving the Spline Landscape Layer and changing its order in the Landscape Layer stack will affects the landscape (unlike Sculpted Layers that do not currently affect the landscape by their order).

Left-Click Hold and Drag Reserve for Splines Landscape Layer within the layer order stack to see how it affects the landscape.

Alpha Value in Reserve for Splines Layer

Reserved for Splines Layer do NOT have Alpha (intensity) controls:

Texturing Landscape Splines

You can have a texture be automatically applied where you have the Spline path. For this you need to have a landscape material with Layer Blend layers setup.

You must be in Manage > Edit Splines mode then go to Details and Select All Segments.

Assign Layer Name from the landscape material:

Important: Spline Textures must be set to Blend Type: LB Alpha Blend and Layer Info to Non Weight Blended Layer, otherwise the texture will show as half-blended. I covered this issue and how to deal with it in UE4 Landscape Layers - Painting Textures tutorial.

If you have separate Splines, each can have a different texture assigned to it.

After assigning a texture Layer Name (for selected Segments) go back to Control Points and adjust Left/Right Side layer Falloff Factor for texture blend offset on each side:

Clearing and Deleting Spline Landscape Layers

By Right-Clicking on Reserved for Splines landscape layer and choosing Clear, you can remove Sculpt, Paint information or All:

If you had a texture applied on the Spline and you Clear the sculpt, texture will remain on the landscape but the sculpted information will be gone:

If you Delete a landscape layer that is Reserved for Splines, heightmap modifications will be gone. However, Splines themselves will still be in your level:

And last you can Remove Reserve for Splines, this will keep the Landscape Layer but remove all Sculpted and Painted information from the terrain:

"UE4 Landscape Essentials" Course

I explain the in-detail the difference between 3 Blend Types and which Layer Info's to use in the "UE4 Landscape Essentials" tutorial course.


Subscribe to receive NEW/UPDATED and FREE "UE5 Beginner's Quick Start Guide" PDF (90 pages).

Subscribe and Get Free UE5 PDF Guide

Visit this page for more info about the guide...

Follow WoLD





About World of Level Design

My name is AlexG. I am self-taught level designer, game environment artist and the creator of World of Level Design.com. I've learned everything I know from personal experimentation and decades of being around various online communities of fellow environment artist and level designers. On World of Level Design you will find tutorials to make you become the best level designer and game environment artist.

Read More »

Home Terms of Use/Trademarks/Disclaimers Privacy Policy Donate About Contact

All content on this website is copyrighted ©2008-2024 World of Level Design LLC. All rights reserved.
Duplication and distribution is illegal and strictly prohibited.

World of Level Design LLC is an independent company. World of Level Design website, its tutorials and products are not endorsed, sponsored or approved by any mentioned companies on this website in any way. All content is based on my own personal experimentation, experience and opinion. World of Level Design™ and 11 Day Level Design™ are trademarks of AlexG.

Template powered by w3.css