Documentation

Everything you need to get productive with Numivo — from installation to advanced species rules. For Unreal Engine 5 and Unity.

Overview

Numivo is an editor toolkit for level design. It consists of three parts: the desktop service (manages your library and presets), the engine plugin (Unreal or Unity) and the shared core connecting both.

The most important principle: Numivo is invisible at runtime. Everything you place bakes down to native engine assets — instanced meshes, foliage, standard materials. Your build has no Numivo dependency.

Installation

Download the installer for your OS from the install page. It sets up the desktop service and can install the engine plugin automatically.

Manual Unity installation via the Package Manager using a Git URL:

// Unity → Window → Package Manager → “+” → Add package from git URL
https://github.com/numivo/com.numivo.leveldesign.git#v1.4.0

For Unreal you can alternatively copy the plugin into the engine plugin folder manually and enable it under Edit → Plugins.

Quickstart: your first scene in 5 minutes

After installing, open the Numivo panel (Window → Numivo). The fastest route to a planted scene:

Drag 3–5 tree assets from the content browser into a new species called “Trees”.
Set density to ~60 % and limit slope to 0–35°.
Pick a brush size with the mouse wheel and paint across your terrain.
Create a second species “Rocks” and give it the rule Avoid: Trees (radius 2 m).
Press B for blend mode and melt the rocks into the terrain.

Tip: every number field accepts both dot and comma as decimal separator — including from the numpad.

Surface Scatter

The scatter places assets on surfaces in a physically plausible way. Each species (asset group) has its own rules: density, slope and height masks, clustering and relations to other species.

The key parameters:

Parameter	Effect
`Density`	Target instances per square meter, modulated by brush strength.
`Slope Mask`	Allowed slope range in degrees. Nothing is placed outside it.
`Clustering`	0 = even distribution, 1 = strong natural grouping.
`Align to Normal`	Instances tilt with the surface instead of standing upright.

Painting: left mouse scatters, Shift + drag erases, the mouse wheel resizes the brush. All strokes are a single undo step.

Mesh Blending

Blending makes meshes visually merge with the terrain. It changes no geometry: the transition is computed in the material from terrain height and texture, and written into standard materials on bake.

Select a mesh, press B and drag the Blend Distance slider. The falloff curve controls how softly the transition fades. “Preview Seams” overlays a heatmap of the transition zone.

Blending needs read access to the terrain texture. For World Partition levels in UE, the affected cells must be loaded.

Grids

The grids tool distributes assets in regular patterns: rectangle, circle, polygon (adjustable side count — 6 sides gives hexagons) and free spline cells.

Each cell can rotate incrementally (“spin”), offset randomly and project onto the surface. Masks cut cells cleanly — ideal for plazas, graveyards, solar farms or orchards.

Measure

The measure tool (M) measures point-to-point, in chains, or as minimum distance between two objects. Snapping locks onto vertices, edges and the grid.

Measurements are stored named in the measurement list and can be exported as CSV. When you leave the tool, all guides vanish — nothing remains in the scene.

Content Browser

The browser indexes your asset library locally (SQLite) and stays smooth beyond a million entries: results are virtualized, thumbnails are generated in a background pipeline.

Search understands names, paths and — with AI tagging enabled — free descriptions like “mossy cliff”. AI tagging is opt-in; without it, no asset ever leaves your machine.

Species & Presets

Species bundle assets with rules. Relations between species control coexistence: Avoid keeps distance, Attract seeks proximity. That's how mushrooms grow at trunks while paths stay clear.

A complete setup can be saved and shared as a preset — a JSON file that transfers between Unreal and Unity:

{
  "species": [{
    "name": "Pine",
    "density": 0.6,
    "slope": [0, 35],
    "clustering": 0.7,
    "relations": [{ "type": "avoid", "target": "Rocks", "radius": 2.0 }]
  }]
}

Shortcuts

Shortcut	Action
`S`	Scatter brush
`B`	Blend mode
`M`	Measure tool
`G`	Grids tool
`Mouse wheel`	Resize brush
`Shift` + Drag	Erase
`Ctrl` / `Shift` + Slider	Fine / coarse slider steps
`Ctrl` + `Z`	Undo last stroke

Troubleshooting

The panel can't find the desktop service.

The service listens locally on port 47615. Check whether a firewall blocks local connections, and restart the service from the tray icon.

The plugin is missing after an engine update.

Engine updates install into a new folder. Run the Numivo installer again — it detects the new version and copies the plugin in.

Thumbnails stay grey.

The thumbnail pipeline runs at low priority. With very large libraries the first pass can take a while; progress is shown at the bottom of the browser.

Scatter looks different in the build than in the editor.

Make sure you baked before building (Bake to Native). Unbaked preview instances exist only in the editor.