A penthouse sales suite in Unreal Engine, built from a description
The living room of an apartment that is not built yet, for buyers to walk through in a headset. It was made as an Unreal Engine 5 project in two runs, and the first request is here word for word.
Michal Takáč 3 min read
This is the living room of an apartment that is not built yet, for buyers to walk through in a headset: low sun across an oak floor, a wall of glass onto a terrace, and a lever that changes day to evening.
It is an Unreal Engine project, so it does not run in a browser. Its app page shows the picture of it.
What it shows
- Unreal Engine 5 with Lumen. The picture is Unreal's desktop renderer.
- Scanned furniture at real size. Furniture, surfaces and plants are scans.
- A Blueprint written by the agent.
- Inside a headset's budget. The request ends by asking what the room costs to draw, and the agent reported 107,476 triangles and 45 meshes, inside its budget for a standalone headset.
How it was made
The project started from the Unreal Engine XR template: an Unreal Engine 5 project for OpenXR headsets, with scanned furniture and props at real size, daylight that bounces, and Blueprints the agent writes.
It took two runs. The first request is below. The second request asked for a brighter day scene and a furnished terrace. The AI was Claude Code.
The request, word for word
This is the text that was sent to the agent to start the project. Nothing was edited for this article.
We are selling the penthouse of our new development before it is built, and buyers will walk through it in a headset in our sales suite. Build its living room.
The room is about 9 by 7 metres with a 3 metre ceiling. One long wall is glass, floor to ceiling in slim dark frames, onto a terrace with a parapet. It is late afternoon and the sun comes in low across the floor.
Furnish it the way an interior designer would for the brochure: a sofa group around a coffee table, an armchair, a sideboard with a few objects on it, plants, a ceiling lamp over the table. Oak floor, light plaster walls. Keep it calm and expensive: few things, well placed, nothing that looks like a toy.
By the entrance, where I start, put a small wall panel with a lever. Lever up is the day scene. Lever down is the evening scene: the sun is gone, the lamps are on and the room is warm.
A sign on the wall names the apartment: Residence 14B.
It has to run on a standalone headset, so keep it light, and tell me what it costs to draw.
Notes and credits
The picture is a capture of the game running on a flat screen. It is Unreal's desktop renderer; a standalone headset uses the mobile renderer, without bounced light.
No frame rate was measured, and it has not been tried on a headset.
Furniture, surfaces and plants are scans from Poly Haven (CC0).
Make your own
Graspable is a desktop app. Describe the scene you want, and the agent builds it as a real project on your computer and checks that it runs. For an Unreal project you need Unreal Engine 5 on your computer.
Download Graspable, and start from the Unreal Engine XR template. More examples are in Made in Graspable.