Prague in 3D

Free flight

Walk the streets and fly over the whole area with no boundaries. iOS accelerometer and gyroscope are supported for intuitive control; remote control of the macOS and tvOS app from an iPhone is on the roadmap.

Open data

The whole city is generated from Prague's open geoportal data. Downloading, processing and publishing are automated on our Linux backend, with a dedicated macOS app to drive every step.

Per-building models

Every building or bridge can be enhanced individually — extra levels of detail, historically accurate variants tied to a year range. Trees are generated parametrically from species, age and the currently selected time, and grow over time.

From the historic core to the outskirts

Over 100 km² of terrain rendered at once — Staré Město, Hradčany, Karlín, Barrandov and beyond. Fly at altitude for the overview, drop down to street level to walk the cobblestones. No scene switching, one continuous world.

Built for Apple, natively

The engine is written against Apple Metal 2 in Objective-C; Metal 3 with GPU-side compute translation is under development. A single 4K frame takes 6–10 ms on a base MacMini M1 — leaving plenty of room for the rest of your app on iPhone, iPad, Mac and Apple TV.

Open data in, detailed city out

Raw geometry and attributes come from Prague's open-data portal. A Linux pipeline downloads, transforms and publishes tiles automatically; hand-edits can then refine individual buildings — including period-correct variants tied to a specific year range.

Engine features

A superfast modular engine for large landscapes and city visualisation, implemented natively in Apple Metal.

Superfast

4K · 6–10 ms

Designed from the ground up for free-fly rendering over large landscapes. A single 4K frame costs 6–10 ms on a base MacMini M1, even before fine-tuning for the target device.

Modular

extensible

Custom or dynamic model types, Metal shaders, render flows and camera types plug in cleanly. Soft shadows, realistic water, real-time weather and simple games built on the engine are all reachable from here.

Apple-native

Metal 2 / 3

Written in Objective-C against Metal 2, with Metal 3 and GPU-side compute translation under active development. Runs on every Apple device on M1+ / A13+ — macOS, iOS and tvOS.

Infinite landscape

tiled

The 3D world is tiled into squares and fragments so that only the exact amount of data needed for the current view is loaded. Background downloads from multiple sources keep the landscape effectively unbounded.

Layered models

LOD

Models are merged into layers — buildings, trees, bridges — each with its own draw ranges, level-of-detail and preload settings. The result is smooth flying across a wide range of devices without one-off tuning per model.

AR / Vision

planned

Not yet implemented here. Our CAD assembly engine already ships with AR, so bringing it to the Prague engine is mostly integration work on the Apple-native stack — visionOS included.