Render Your Home Assistant Floor Plan with Live Lighting: A Sweet Home 3D Plugin
If you've ever stared at your Home Assistant dashboard and thought, "I wish this floor plan actually showed the lights turning on and off, instead of just a static image," you're not alone. Most floor plans are nice to look at, but they don't react to your smart home's state.
Enter this project: a Sweet Home 3D plugin that takes your floor plan and brings it to life with live lighting data from Home Assistant. It's not just a static SVG export — it's a dynamic, real-time visualization of where your lights are actually shining.
What It Does
This plugin bridges Sweet Home 3D (the open-source interior design app) with Home Assistant's API. You design your floor plan in Sweet Home 3D, add light sources (like lamps, ceiling lights, or windows) that correspond to your real-world smart lights, and then the plugin connects to your Home Assistant instance. When those lights change state — whether dimmed, turned on, or set to a color — the plugin updates the 3D scene in real time.
The result? A floor plan that visually reflects the actual lighting in your home. You can see which rooms are bright, which are dim, and even get a sense of the color temperature.
Why It's Cool
This isn't just a gimmick. It's a genuinely useful way to get a quick, intuitive overview of your home's lighting state without scrolling through cards or checking individual entities. Here's what makes it stand out:
- Live, not static: The floor plan updates instantly when lights change, so you can see the effect of an automation or a voice command.
- Sweet Home 3D integration: For anyone who already uses Sweet Home 3D to design their home layout, this is a natural extension. You don't need to learn a new tool.
- Color accuracy: It respects both brightness and color values, so a warm-white lamp looks different from a cool-white one on the plan.
- No cloud dependencies: Everything runs locally — your Home Assistant data never leaves your network.
For power users, this could also be the foundation for a more immersive control interface: imagine clicking on a lamp in the 3D scene to toggle it, or seeing visual feedback from a motion sensor.
How to Try It
Getting started is straightforward if you already have both Home Assistant and Sweet Home 3D set up. Here's the quick version:
- Install the plugin from the GitHub repository.
- In Sweet Home 3D, create a floor plan with light fixtures that match your real lights (use the "Light" tool).
- Configure the plugin with your Home Assistant URL and a long-lived access token.
- Map each fixture to its corresponding entity ID (e.g.,
light.living_room_ceiling). - Hit "Connect" and watch the scene update as you toggle lights in HA.
The README includes detailed steps, screenshots, and examples of the mapping configuration. It's not plug-and-play for absolute beginners, but if you're comfortable editing a simple JSON file, you'll be up in minutes.
Final Thoughts
This is one of those projects that scratches an itch you didn't realize you had — until you see it working. For developers and serious home automation enthusiasts, it's a great example of how combining a desktop app (Sweet Home 3D) with an automation platform (Home Assistant) can produce something genuinely useful.
If you're into home automation and visualization, give it a spin. You might find yourself redesigning your floor plan just to see more lights.
Follow @githubprojects for more developer tools and open-source projects.