How to Build Your Own Mountain with a Heightmap

Do you want to build a giant mountain for your Fortnite island? Or maybe a deep cave system? You can draw the shape of your land using a special picture called a heightmap. It is like coloring a page, but the colors become hills and valleys. Let’s learn how to make your own custom terrain.

What You'll Learn

• What a heightmap is.
• How to turn a black-and-white drawing into 3D land.
• How to use the Scene Graph to organize your world.
• How to place your new mountain on your island.

How It Works

Imagine you are baking a cake. You have a pan. You pour batter into it. The shape of the batter matches the shape of the pan. A heightmap is like the pan. It tells the game engine where to put the ground.

A heightmap is a simple square picture. It is black and white. Each pixel (tiny dot) in the picture has a color. The color tells the game how high that spot should be.

Think of it like a topographic map. White means high up. Black means low down. Gray means in the middle. If you draw a white circle, you get a hill. If you draw a black circle, you get a crater. This is very helpful. It saves memory. The computer does not need to store every single rock. It just stores the picture.

We also need to talk about the Scene Graph. This is just a fancy name for the family tree of your island. Your island has a root. The root has branches. Each branch is a piece of land or a building. When you add a heightmap, you are adding a new branch to this tree. It helps the computer know where everything lives.

Let's Build It

We will create a custom heightmap and place it in your level. We will use the Landscape tool. This tool lets you paint the land.

Step 1: Open the Landscape Tool

1. Open UEFN (Unreal Editor for Fortnite).
2. Go to the Palette panel.
3. Search for Landscape.
4. Drag a Landscape actor into your scene.

Now you have a flat piece of ground. It is like a blank canvas.

Step 2: Create the Heightmap

1. Click on the Landscape actor you just placed.
2. Look at the Details panel on the right.
3. Find the Landscape section.
4. Look for Heightmap or Import Heightmap.
5. You can draw your own shape here. Or you can import a picture.

Let’s try drawing a simple hill.

// This is a conceptual example of how the engine reads the map.
// You do not type this code. You use the editor tools.

// The engine looks at the pixel color.
// White pixel = High ground.
// Black pixel = Low ground.

// Imagine a pixel at position (10, 10).
// Its color is white.
// So the ground at (10, 10) is high.

// Imagine a pixel at position (10, 11).
// Its color is black.
// So the ground at (10, 11) is low.

// The engine connects these points.
// It creates a slope.
// It creates a hill.

Step 3: Adjust the Size

Your hill might be too small or too big. You can change this.

1. In the Details panel, find Scale.
2. Change the Z value. This makes the hill taller.
3. Change the X and Y values. This makes the hill wider.

Step 4: Add Some Trees

Now you have a hill. Let’s make it look nice.

1. Go to the Palette again.
2. Search for Tree.
3. Drag a tree onto the top of your hill.

The tree will sit on the ground. It will follow the shape of your hill. This is because of the Scene Graph. The tree is a child of the world. The world has the hill shape. So the tree sits on the hill.

Try It Yourself

Can you make a crater? A crater is a hole in the ground.

Hint: Think about the colors. White is high. Black is low. What color should you use for the center of the hole?

Recap

• A heightmap is a black-and-white picture that controls the shape of your land.
• White pixels make high ground. Black pixels make low ground.
• The Scene Graph helps organize your island like a family tree.
• You can use the Landscape tool to import or draw your heightmap.

References

• https://dev.epicgames.com/documentation/en-us/uefn/UE/building-virtual-worlds/landscape-outdoor-terrain/creating-landscapes/creating-and-using-custom-heightmaps
• https://dev.epicgames.com/documentation/en-us/fortnite/unreal-editor-for-fortnite-glossary
• https://dev.epicgames.com/documentation/en-us/uefn/unreal-editor-for-fortnite-glossary
• https://dev.epicgames.com/community/snippets/rmmj/fortnite-height-meter-for-onlyup-style-maps
• https://dev.epicgames.com/documentation/en-us/fortnite/creating-custom-skilled-interactions-in-unreal-editor-for-fortnite