UDK: 2 Quick Ways to Modify and Form Landscapes

Category: UDK

February 17, 2015

There are some workflows that will generate UDK landscape heightmaps very quickly for you. Such as using exterior software then export/import those heightmaps into UDK. Another solution is to use Photoshop Clouds Filter.

But, there are other ways to modify and form your landscape in UDK very quickly, without using additional software or doing it manually. You can do it all inside UDK.

In this tutorial you will learn how to generate and modify UDK Landscape heightmap very quickly to generate a random pattern of hills, mountains, peaks and valleys. It will give you a good starting base for a landscape.

These two tools in UDK are Landscape Noise Tool and Erosion Tool.

Important to note, that these two tools are a great start to generate a heightmap pattern randomly but you will still have to continue to refine and detail after.

Preliminary Work

Use one of the UDK Templates as a base. This way you will have a light, skybox, fog and Lightmass Importance Volume:

Next, create a landscape to work with. For this tutorial I used landscape size of 505x505:

Place a skeletal mesh for judging scale:

Technique #1: Noise Tool

Noise tool will add random patterns of noise throughout the landscape. Here are the settings to set:

Set Tool Strength: higher value will increase the intensity of heightmap elevation. Bring this to lower value (.01 - .1) to control the elevation
Set the Brush Size: larger or smaller, depending on the area
Use Addition, Subtraction or Both to raise/lower/raise+lower the heightmap. I start with Addition first.
Set Noise Scale: lower value will add more detail noise to smaller sections, higher value will increase the noise scale to larger areas - higher value will make Noise Detail less noticeable

Press Ctrl+Left Mouse Click to paint noise over the landcape. With the settings above, you will begin to generate random height patterns. The key is to dabble with the mouse click over areas, and not left-click and drag. This will give you more control.

Only Noise Tool heightmap generation, after 1 minute worth of work

Using Noise Tool is just a start. Now, come back through with Smooth, Paint and Flatten Tools to refine. Continue to use Noise and Erosion to add additional detail.

Technique #2: Thermal Erosion

Erosion simulates how wind, sun and water naturally erodes the landscape.

Set Tool Strength: higher value will increase the intensity of heightmap elevation, set this anywhere from (.4 - .7)
Set the Brush Size: larger or smaller, depending on the area
Use Addition, Subtraction or Both to raise/lower/raise+lower the heightmap. I start with Addition first - this builds up the heightmap elevation faster
Set Noise Scale: lower value will add more detail noise to smaller sections, higher value will increase the noise scale to larger areas - higher value will make Noise Detail less noticeable or more smoother terrain
Leave the rest of Erosion Settings at default

Press Ctrl+Left Mouse Click and Drag over the landscape. Build up the landscape by dragging over the terrain and seeing how it forms.

After couple of minutes of work using Thermal Erosion only

As with the Noise Tool, continue after this to refine and reshape the terrain to final version by using all other landscape tools (Paint, Smooth, Erosion, Noise and Flatten).

Hydraulic Erosion: Hydraulic Erosion is not very good for this type of use. The tools becomes very slow and it doesn't produce enough of height variation. Noise and Thermal are much better for quickly modifying your heightmap.