Interactive 3D Travel Guide Map of Downtown Bangkok – Cesium/OSM Project Description (The Hook & Rich Details) Basic Objective: We are seeking an expert 3D Map Developer to create a dynamic, photorealistic, interactive 3D travel guide map of the R District (Ratchaprasong) in downtown Bangkok. The Vision: This is not a generic GPS map. We are creating an immersive digital "experience platform" for both tourist and business travelers. Your task is to build a functional and technically correct city model that is also creatively designed to showcase the vibrant experiences, pedestrian connectivity, and upscale lifestyle of the district. Detailed Key Features to Develop: 3D Base Map Construction: Coverage: Focus specifically on the R District and 2 KM radius (Ratchaprasong intersection) as shown in the provided PDF map. Buildings: Photorealistic or high-quality stylized 3D models of all major buildings (e.g., Centralworld, Siam Paragon, Gaysorn Village, Centara Grand, etc.). Connectivity: Accurately map all streets, roads, and sidewalks, but crucially, prioritize the R Walk (elevated pedestrian walkway system), showcasing it as a clear, premium, connected pathway. Dynamic Experience Overlays: Interactive Hotspots/Pins: Create custom-designed interactive pins for key locations. Themed Categories: Users must be able to filter pins by experience: Luxury Shopping: (Gaysorn, Paragon, Centralworld). Culture/Shrines: (Erawan Shrine, etc., with small photo popups). Dining & Nightlife: (Rooftop bars at Centara, fine dining). Business & Hotels: (Meeting venues, entry points). Multimedia Popups: When a user clicks a pin, it should open a clean popup containing: a short description, 1-3 high-resolution photos, a web link, and perhaps a 360° photo (if available). User Experience (UX) and Navigation: Perspective Views: Default to an oblique "fly-around" view but allow smooth tilting and 360° rotation. Pre-Set Tours/Routes: Develop 2-3 "guided paths" (e.g., "The Luxury Shopping Sprint," "A Shrine Tour," "Connectivity for Business Travelers"). When selected, the map camera moves smoothly along the designated route. Custom Map Style: Use a custom base map style (similar to the provided PDF's aesthetic: clean gray, vibrant orange for pathways) rather than default satellite imagery. Required Technical Skills/Stacks Candidates must demonstrate expertise in at least one of the following technical pathways and explain why it is the best fit for a web-based interactive guide. Primary Pathway: CesiumJS (with 3D Tiles/PBR) + OpenStreetMap data. Alternative Pathway: Mapbox GL JS (using their 3D building/terrain tools). Secondary Option: Three.js or Babylon.js (for custom 3D mesh building, if paired with GIS data).