Lumina+: An Integrated AI-Driven Interior Design Platform with Generative Redesign and Web-Based Augmented Reality

Professional interior design visualisation haslong required expensive software and trained practitioners. This paper describes Lumina+, a browser-nativeplatform that puts photo-quality room redesign, 2Dfurniture layout, and augmented reality preview into asingle web application. The system uses Google’s Gemini2.5 Flash multimodal model to accept a room photograph and a style prompt, then return a photorealisticredesigned image with a written design rationale. AFabric.js canvas lets users search, place, and repositionfurniture items, with layouts saved to Cloud Firestoreand shareable via public links. The AR view composites interactive Three.js furniture meshes over a livedevice camera feed using the WebRTC getUserMediaAPI, requiring no dedicated hardware. The architectureis entirely serverless: Firebase handles authenticationand persistence while all business logic runs in the clientbundle. Firebase security rules enforce per-user dataownership. The design choices documented here forma reusable pattern for embedding generative AI intocreative web applications.