# Pascal Scene Graph: Building Digital Twins with Open-Source Data

- Original post: https://www.twitter.com/i/status/2115809363151773979
- Source account: [@pascal](https://x.com/pascal)
- Source language: English
- Duration: 2:45
- Published: 2026-10-30
- Canonical URL: https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data

## Transcript

[0:00](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data) This is Pascal. This is also Pascal.

[0:09](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=9) This is Pascal too. Different buildings, different outputs, one structure underneath, because Pascal isn't a renderer.

[0:19](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=19) It's the DOM of a building, a ground truth you can build any experience or simulation on top of.

[0:26](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=26) We call it the scene graph. Everything is a node.

[0:29](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=29) Every wall, window, door, and a piece of furniture is a node with properties. A window knows its size, its material, which wall it's in, and which way it faces.

[0:40](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=40) Nodes live in zones. A zone is a room or any space you define, an open kitchen, a hallway, a terrace.

[0:48](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=48) Zones carry their own data too, area, floor type, what they're used for, and zones can be grouped into units.

[0:55](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=55) So a condo or a hotel room is one thing you can point at.

[0:58](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=58) Zones sits on levels. A level is more than a floor number.

[1:03](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=63) It has its height, its elevation, its own structure.

[1:06](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=66) Stack them, and you get the vertical shape of the building.

[1:09](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=69) Levels make a building. The building node doesn't duplicate what's below it. Its height, its level count, its entrances all come from its children. What it owns is what belongs to the building as a whole, its footprint, its orientation, its name.

[1:24](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=84) And finally, buildings sit on a site. The site is where it all ends in the real world.

[1:30](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=90) Coordinates, the plot, which way north is, that's what lets you compute sunlight or put the building on a map.

[1:37](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=97) Collections cut across all of it, all the lights, all the appliances, whatever you define.

[1:42](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=102) The render is just one way to look at it, and because everything is a node, you can query the building the way you'd query the DOM.

[1:50](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=110) Give me every window facing south. Turn the lights off in the kitchen. Show me the HVAC system.

[1:56](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=116) No ray casting, no guessing. You ask the building, and it answers. That's what makes a real digital twin possible, not a 3D model you look at, but a building you can simulate, automate, and reason about. Sunlight, energy,

[2:11](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=131) Wi-Fi coverage, home automation, a listing that's actually the building. Every building in the world could have one, and every one of them could run your experience. And the graph is the product, not the render. It keeps evolving. New node types, new properties, new relationships between them. Anything built on it inherits all of that

[2:31](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=151) for free, inside the editor as plugins or outside it as anything that reads the graph. Pascal is open source, the scene graph, the editor, the plugins. Come and contribute.

[2:42](https://www.translate.mom/transcript/YANKurxtE1Oj/en/pascal-scene-graph-building-digital-twins-with-open-source-data?t=162) It's all on GitHub.