iCity Blender Add-on: Procedural City in ~30 Seconds

A viral August 2026 demo showed a procedural city appearing in Blender in roughly 30 seconds — roads, towers, parks, and traffic lights included. The tool behind it is iCity, a Geometry Nodes add-on from Parametra (developer Hothifa Smair) that turns a road sketch into a production-ready urban block layout. If you build driving sims, archviz flythroughs, VFX backgrounds, or AI training environments, iCity is one of the fastest ways to block out a believable city without hand-modeling every facade.

This explainx.ai guide is the step-by-step path: install, generate, customize roads/towers/parks/traffic, export, and fix the failures that show up in real projects.

TL;DR — iCity at a glance

What you need before you start

iCity sits in the same "world building" lane as Nvidia Cosmos physical-AI environments and open driving sims like Hop Earth — but here you author the layout in Blender instead of pulling satellite tiles.

Step 1 — Install the iCity add-on

1. Download iCity 1.5 from Blender Market after purchase.
2. In Blender: Edit → Preferences → Add-ons → Install… and select the zip.
3. Enable iCity in the add-ons list.
4. Open a new scene; iCity adds its panel and drops an iCity Base object — the mesh you edit to define roads.

If the panel is missing, confirm you are on Blender 4.4+ and that no other city-generator add-on conflicts with the same hotkeys.

Step 2 — Draw the road network (foundation layer)

Everything in iCity flows from roads:

1. Select iCity Base and enter Edit Mode.
2. Extrude edges or draw curves that define your street grid — main arteries first, then side streets and alleys.
3. Exit Edit Mode; Geometry Nodes convert the mesh into procedural road geometry with intersections, sidewalks, and block boundaries.

Road hierarchy tips (from Parametra docs):

Roads stay fully procedural — move a curve and blocks, buildings, and sidewalks regenerate. Avoid extremely sharp corners until you need them; smooth curves produce cleaner intersections.

Step 3 — Generate blocks and assign district types

Once roads close polygons, iCity auto-detects blocks. In the iCity UI, assign each block a type:

For a 30-second block-out: draw one main loop, set inner blocks to Towers, ring blocks to Grid, drop a Parks island in the center.

Step 4 — Customize buildings, materials, and atmosphere

Open the iCity property panels to tune:

• Height ranges and density per block type
• Parallax rooms — lit window interiors without heavy geometry
• Night Mode — streetlights, window glow, cinematic ambience (single toggle)
• Wet ground materials — reflective pavement for rain or cyberpunk shots

Use Light Mode while iterating layout; disable it before final renders or export.

Step 5 — Add traffic (and connect to sim pipelines)

iCity integrates with Parametra's broader ecosystem — Cars and traffic-oriented exports bridge Blender layouts to simulators. Practical workflow:

1. Finalize road widths and lane logic in iCity.
2. Export the road network (GLB/FBX).
3. Import into your engine or traffic tool (Unreal, Unity, specialist sim) and attach vehicle spawners / AI traffic on the imported splines.

For Unreal-heavy pipelines, see Unreal Engine MCP + agent tooling for how teams automate import and iteration loops.

Step 6 — Export without freezing Blender

Heavy cities can stall the viewport. iCity's background export runs GLB/FBX/USD jobs without blocking the UI:

1. Set export format and scale in the iCity export panel.
2. Start background export; continue editing other objects if needed.
3. Verify mesh names and road splines in your target app — re-import once if axis or scale differs.

Archviz flythrough path: export USD or FBX → render in Blender (Eevee/Cycles) or re-import to your viz stack.

Game / sim path: export GLB → engine import → navmesh / traffic graph on road centerlines.

Troubleshooting common iCity issues

Parametra documents that custom external assets are unsupported — if you need a specific hero building, place it in an Empty block and keep procedural context around it.

What people are asking

Is iCity worth $78 vs free city scripts?

If your time cost is more than a few hours of manual modeling per project, yes — especially for iterative client reviews where road moves must regenerate districts instantly. Free scripts rarely bundle export, night mode, parallax interiors, and intersection logic in one GN stack.

Can AI coding agents help with iCity?

Agents excel at export automation, render-script boilerplate, and Unreal/Unity import checklists — not at replacing the viewport road draw. Pair iCity with agent skills for 3D pipelines when you document how city assets flow into your build.

iCity vs manually kit-bashing KitBash3D / Quixel?

Kitbash is art-directable hero pieces; iCity is layout-first procedural massing. Common pattern: iCity block-out → hero assets hand-placed in Empty blocks → export.

Related on explainx.ai

• Nvidia Cosmos 3 — open physical-AI world models
• Hop Earth — drive-anywhere satellite map game
• Unreal Engine 5.8 + Claude/Codex MCP integration
• Google Earth flight simulator on the web
• Archify — verifiable architecture maps for agent workflows
• What are world models?

External references: iCity documentation · icity3d.com · CG Channel iCity 1.5 overview

Pricing, Blender version requirements, and feature names reflect Parametra's iCity 1.5 documentation and Blender Market listing as of August 31, 2026.