TerrainForge
Build terrain from a node graph or from a real place, preview it live, and import it as a World Partition landscape with rivers, lakes and paint layers.
Describe a terrain as a graph of nodes, or start from a real square of the Earth, and get a World Partition landscape in a new map: heightmap, paint layers, lakes and rivers as engine water bodies, and the masks a biome or PCG setup needs.
Everything is computed by a native engine inside the Unreal editor. Nodes that have a GPU kernel run on the graphics card when one is available. No other program starts, nothing is sent to a service, and no third-party terrain tool or licence is needed.
| Plugin | Role | Licence | Version |
|---|---|---|---|
| TerrainForge | coreThe subsystem. Install this one. | Paid | 0.1.0 |
| TerrainForgeToolset source | toolsetThe same subsystem as typed MCP tools, for an agent. Adds nothing of its own. | Open | 0.1.0 |
In preview, not released yet. Every page in this section is written against the plugin source as it will ship. The version chips at the top of each page appear with the first release.
Two plugins
| Plugin | Licence | What it is |
|---|---|---|
| TerrainForge | Paid. Free while it is in preview. | The whole product: the node engine, the definition editor, GPU kernels, the map, real-world data and the landscape importer. |
| TerrainForgeToolset | Open source, Apache-2.0 | The same operations as typed MCP tools, plus agent skills. It adds no capability of its own. See agents. |
What TerrainForge produces for you (heightmaps, masks, landscapes, levels) is yours to use and ship. The free preview licence lasts while TerrainForge is free. When the preview ends, using it needs a bought licence. Everything you made while it was free stays yours to use; work made after that without a licence is not licensed.
A toolset stays open even when the plugin it drives is paid. The distribution page says why.
TerrainForge is one plugin with six editor modules:
| Module | Does |
|---|---|
TerrainForgeCore | The engine: fields, the node library, the scheduler, coarse-to-fine builds. Plain C++. |
TerrainForgeNative | Runs previews and builds off the game thread. |
TerrainForge | The Terrain Definition asset, its editor, takes, export and landscape import. |
TerrainForgeShaders | GPU compute kernels. Without a usable GPU, every kernel runs on the CPU. |
TerrainForgeMap | The map: place search, relief, source coverage, the square you import. |
TerrainForgeGIS | Real-world data: discovery, site check, import and level build. |
What you get
- A Terrain Definition asset. Its graph and world settings are the recipe. It is a normal asset: saved, diffed, undone.
- An editor for it, with tabs for the node library, the flow graph, the node inspector, a 3D terrain viewer, world and biome settings, GIS import, export, and a build monitor.
- A catalog of nodes: generators, placed landforms, filters, erosion and glaciers, geology, rivers, lakes, coast, masks and colour. Each one is documented in the node reference, which is generated from the source.
- Presets. Sixteen classic graphs (ridges, canyons, islands, dunes, crater lakes, branching rivers) and two eroded alpine ones: Alpine valleys (eroded) at 4 km and 4033 samples, and an 8 km layout at 8129.
- Takes. Every build writes a new folder of files and never overwrites an old one.
- A landscape importer that makes a new World Partition map from a take.
- Real-world terrain. Elevation from national and global services, land cover and OpenStreetMap masks, for any square from 500 m to 50 km. See GIS.
- Level projects. A check of whether a real place can become a level, and a build that turns it into a 1 m grid with paint layers and water. See levels.
What it deliberately does not do
- Overwrite a map. Every landscape import creates a new map at an unused path. The importer refuses an existing path, an open map with unsaved changes, and a running Play In Editor session.
- Erode real elevation on import. Imported elevation arrives as a source node. Whatever runs after it is up to your graph.
- Carve terrain from OpenStreetMap by itself. OSM features become masks and vectors. They shape nothing unless your graph uses them.
- Survive the editor closing. A build runs inside the editor process. If the editor closes, the build stops and cannot be reconnected; build again.
- Ship in your game. Both plugins are editor-only. The landscape, the water bodies and the textures they create are ordinary Unreal content.
- Give you a production material. The landscape material the importer creates paints each layer a flat colour, for inspection. Water uses the engine's own defaults.
- Match another tool's feature list. TerrainForge is not a clone of a standalone terrain application, and does not claim parity with one.
Takes
A build writes a take to
Forge/Library/TerrainForge/<definition>/<job id>/ in the project. A take is
never overwritten. It holds:
| File | What it is |
|---|---|
height.png, height.r16 | The heightmap, 16-bit. Row 0 is north, column 0 west. |
<Layer>.png | One 8-bit weight map per paint layer. At every pixel they sum to exactly 255. |
biome_<rule>.png | Normalised coverage of each biome rule. These add up. |
pcg_<rule>.png | Independent suitability of each rule, for PCG. These overlap. |
data_*.png | Slope, aspect, flow, wetness, deposition, distance to water, snow, water, moisture. Masks, not calibrated measurements. |
graph_<name>.png | Any node output you asked for as a named 16-bit map. |
water.json, water_surface.obj, water_bottom.obj | Lakes and rivers as outlines and meshes. |
preview.png, validation.json, manifest.json | A hillshade, the checks the build ran, and every file with its hash. |
Heights decode as min + code / 65536 × (max − min), with min and max
from the world settings. A build fails rather than clip a height outside
that range, so leave room in it.
Waterfalls in water.json are candidate locations, not simulated falls.
GPU compute
The Compute setting decides where nodes with a GPU kernel run:
| Policy | Behaviour |
|---|---|
| Auto (default) | The GPU where a node has a kernel, the device is available and the grid is large enough to gain. The CPU otherwise. |
| CPU Only | The CPU everywhere. A node set to gpu runs on the CPU with a warning. |
| Prefer GPU | The GPU wherever a kernel exists, at every size. |
| Reference | The CPU everywhere, in each kernel's most precise mode. Slower. |
GPU kernels exist for Erode (with Geology connected too), Scree in parallel
mode, Hydraulic's parallel droplets, Weathering's droplet stages, Gaussian blur
and flow accumulation. A GPU kernel that cannot run falls back to the CPU
by itself, and the build monitor says which device ran each node. A node's
own compute parameter can still ask for the CPU.
Each GPU kernel is tested against its CPU version, so a graph keeps its look when the device changes. A pass whose inputs have not changed is reused from the cache whichever device made it.
One measurement, on one high-end laptop GPU: a full 4033 take of the alpine preset took about 79 s with Auto and 233 s with CPU Only. Other cards differ.
Requirements
- Windows, 64-bit, and Unreal Engine 5.8. Both plugins are editor-only.
- The engine's Water and Procedural Mesh Component plugins. TerrainForge enables them.
- A GPU is optional. GPU compute uses a DirectX 12 card (Shader Model 5 or later; some paths use Shader Model 6). Without one, everything runs on the CPU and the graph keeps its look.
- Memory to match the grid. The World & biomes tab shows an estimate of a build's peak memory before you start it; a 16321 build needs about 16 GB. A 4033 GIS import or level build needs about 1.2 GB free.
- Internet access only for the map and real-world data. Nothing else in TerrainForge opens a connection. See internet access.
Settings
Under Editor Preferences → Plugins, all per user:
| Page | Holds |
|---|---|
| TerrainForge Native Engine | Cache budget (8 GiB), progressive preview (a 257 × 257 preview first), drainage water in previews, Compute, GPU memory budget, concurrent nodes, working memory budget per build, and spilling waiting results to disk. |
| TerrainForge | Job timeout: the longest a build may run (an hour by default) before it is stopped and reported as failed. |
| TerrainForge GIS | Overpass servers, extra profile folders, the elevation tile cache limit, and Clear GIS caches. |
| TerrainForge Map | Default basemap, relief overlay, keys for keyed basemaps and place search, and the tile cache. |
Known limits
The limits this preview ships with, as its own release notes state them:
- Builds do not survive an editor restart. Build again.
- Seam normals after a headless import can differ on steep slopes until the editor's next edit-layer merge. The engine blends them at runtime.
- Water saves are slow: each water body takes 3 to 70 seconds to save during an import.
- The first landscape material is plain: flat layer colours, and the engine's default water materials.
- Biome edge streaks. With the default moisture setting, Forest, Meadow
and Soil can streak on smooth slopes near the map edges. The biome setting
moisture_wetness: mfdremoves them; the alpine presets use it. - A busy OpenStreetMap server. The public Overpass server is shared; imports wait, retry and say so. You can add your own server.
- UK and Netherlands datum. Elevation there is placed to about 2 m and 1 m, because the national datum grids are not applied.
- It is a preview. File formats, settings and saved data may change between versions. Keep backups.
Where to go next
Getting started
Install, start from a preset, preview, build, import a landscape.
Node reference
Every node, its ports and every parameter, generated from the source.
Real-world terrain
The map, Discover, elevation sources, land cover, OpenStreetMap and licences.
Level projects
Check a real place against a profile, then build a 1 m level from it.
Agents
The MCP tools and skills, with example requests.
Troubleshooting
The failure messages, quoted, and what each one means.