UE4: 9 Things Every Procedural Auto-Landscape Material Must Have

Category: UE4

November 11, 2020

Before I knew anything about Auto-Landscape Materials, I thought you only needed to have a couple of textures.

I quickly realized that this wasn't enough.

In addition to automatically changing textures based on slope, I needed:

Edge blend control between textures
Automatically texture terrains based on height
Automatically spawn foliage
Ability to paint manual texture layers
And much more...

Here are 9 things every Auto-Landscape Materials must be able to do.

Video Tutorial

1. Must Assign a Texture Based on Slope/Angle

The basis of any Auto-Landscape Material is the ability to automatically texture terrain based on its slope (angle). This can be done few different ways in the Material Editor.

But the most reliable way I found is to use World Aligned Blend node. This material expression is the foundation of all Auto-Landscape materials I create.

The two important inputs to use with World Aligned Blend are Blend Bias and Blend Sharpness.

Blend Sharpness: controls the blend sharpness between the two textures
Blend Bias: controls the slope or the incline (you'll want to keep this value in the negative range)

2. Must Have 2 or 3 Textures

Auto-Landscape Materials can have 2 or 3 textures that will automatically change on your terrain based on slope (angle).

2-texture Auto-Material is the simplest and most effective. Here is an example of 2 texture auto-landscape material.

3-texture Auto-Material is a bit more involved. First texture is used for flat areas, third texture is used for angled slopes and second texture is used to blend between the first and third texture.

In this example I have 3-texture Auto-Material - grass, dirt and rock. Grass is on the flat parts of the landscape, rock is on the slopes and dirt is the texture in-between grass and rock.

You can have more than 3-textures but it doesn't add any more functionality other than introducing another blend in-between texture. This becomes more difficult to manage.

I stick with 2 or 3 texture Auto-Landscape Material setup and this has been more than enough.

3. Must Assign a Texture Based on Height

World Aligned Blend node only works based on slope or angle of the terrain.

If you want to assign automatic texture to the landscape based on height you'll have to use Absolute World Position node and combine it with World Aligned Blend setup.

There are other additional controls that will need to be added after this to make sure the height of the texture can be naturally blended using a Mask, otherwise you'll have a solid line across landscapes at a certain height.

But with a Mask blend controls you can have a texture appear at a certain height and naturally merge with the rest of the terrain.

4. Must Have Ability to Paint Textures Manually

Auto-Landscape Material by itself does a great job texturing your terrain automatically.

But you can have more control if you add manually painted texture layers. This will allow you paint extra textures on top of automatically generated ones such as extra detail or roads and pathways.

You do this by adding Landscape Layer Blend node and creating Landscape Layer Info into the existing Auto-Landscape Material.

5. Must Have Controls to Blend Between Textures

Auto-Landscape Material by default will have a soft blend between textures.

It will work most of the time but what if you want a hard edge blend like so?

You'll have to set this up in the Material Editor by adding Edge Intensity adjustment with a Power node then using a texture Mask for natural appearance.

6. Must Spawn Foliage Automatically

If you have environments where foliage isn't required, Auto-Landscape Materials will work as is. But for environments where you also need to spawn foliage at the same time along with Auto-Landscape Materials then you need to add this functionality.

This will allow you to spawn foliage on your terrain, automatically without having to use Foliage Tool or Foliage Volumes, unless of course you want to.

So for example you could spawn grass foliage and flowers on the grass texture and when Auto-Landscape Material changes to dirt texture on steeper slopes it will automatically spawn rocks and dead grass.

To do this you have to use the Grass node.

If you decide to sculpt your landscape, Auto-Material will apply appropriate foliage and texture the terrain automatically.

Very powerful technique and this alone will save you a lot of time.

7. Must Remove Spawned Foliage on Manually Painted Layers

You will run into a problem if you have foliage being spawned on the terrain automatically when painting texture layers manually, it will not remove the spawned foliage.

Cobblestone was painted on the landscape with grass spawning on top

You must add the ability to have foliage removed as you manual paint texture layers by using the One Minus node and Landscape Layer Blend node with Multiply. It is a bit tricky to setup if you don't know how but once you do, it is easy to re-use across any Auto-Landscape Material.

Here I painted cobble stone paths on top of Auto-Landscape Material and grass foliage meshes were removed automatically.

8. Must Control Texture Tile Near and Far Away

Biggest problem with landscape materials is texture repetition. This applies not only to Auto-Landscape Materials but to any landscape materials.

Terrain textures look good near the player but at a distance, the repetition becomes extremely noticeable.

There are many tricks you can implement to reduce and eliminate this repetition.

First you need to set up to control tiling. Then you need to control tiling for different distances of the same texture. For textures up-close near the player and textures far away at a distance. And on top of all that you should use Macro/Micro trick explained in this tutorial.

Your Auto-Landscape Material should have all of the above tricks implemented to completely remove any noticeable texture tiling.

9. Must Have Parameters for Material Instance

You want to create Auto-Landscape Material once and then re-use it over and over again for different projects and on different landscapes.

For this to happen you must add various parameters within the Material Editor to allow for control of changing Albedo and Normal Map textures, adjust texture blends, change the slope or angle where textures will appear on and much more.

Here is a list of all parameters I have set up in my Master Auto-Landscape material: