Create a staggering Three.js vision of Atlantis not as a ruin, but as a living underwater capital: an immense luminous civilization beneath a crystal-blue ocean, built around concentric boulevards and canals, coral-overgrown palaces, glass domes, golden towers, illuminated plazas, gardens of sea life, schools of fish and citizens moving through protected spaces, while a colossal whale glides overhead and sunbeams reach down from the surface. The first frame must deliver the entire unbelievable idea instantly: a magnificent inhabited city below the sea, not a few broken columns or a generic aquarium with buildings.
The scene should feel composed of a billion tiny marvels: patterned streets, columns, domes, arches, mosaic plazas, shell and coral detail, windows, lanterns, bubble trails, kelp forests, sea fans, rays, turtles, fish schools, vehicles or elegant submersible transports, interior silhouettes, drifting particles and moving caustic light. Use procedural geometry, dense instancing, layered shaders and level of detail to generate an astonishingly complete underwater world while keeping it fluid to explore.
If you use Three.js, add an import map before the module script mapping "three" and "three/addons/" to the same pinned version, and import only via those names. Generate all architecture, water volume, caustics, marine life, people, plants, materials, lighting and animation procedurally without external assets. A jewel-like micro-voxel craft aesthetic may enrich architecture, coral gardens and mosaics, while the water, whale, rays and sunlight must remain graceful, continuous and cinematic.
#### FIRST FRAME - THE CITY THAT SHOULD NOT EXIST
- Open directly from a grand elevated underwater viewpoint on the rim of the capital: a foreground coral terrace and statuesque architectural edge frame a vast radiant city below, with concentric districts, domes and tower clusters leading toward a central palace; above it all a giant whale passes through bright surface rays, instantly establishing ocean scale.
- Make the city alive and luminous rather than dark: blue and turquoise water, warm golden architectural lights, pearl and jade structures, coral colors, bright caustics, clear silhouettes and schools of fish crossing near the camera.
- Include multiple depth layers: close reef-and-building craftsmanship, central ceremonial city, distant residential rings and monumental outer arches dissolving into blue water, plus the shimmering surface far above.
- No slow discovery, darkness, disaster story, empty ruin or UI exposition. Atlantis is already thriving and the first image is the reward.
#### AN UNDERWATER CAPITAL WITH URBAN GRANDEUR
- Construct a coherent city plan visible from the hero view: grand central domed palace, concentric avenues or canal rings, radiating bridges, civic plazas, temple-like towers, glass habitats, terrace gardens, transit routes, gateways and outer neighborhoods merged with reefs.
- Make architecture impossibly lavish: pearl-stone columns, golden ribs, translucent domes, shell spirals, carved sea motifs, mosaic paths, balustrades, glowing windows, arched bridges, fountain-like bubble vents, coral cultivated along terraces and enormous statues suggested in silhouette without clutter.
- Populate protected interiors and breathable public spaces through glowing domes and windows: tiny residents crossing plazas, gardens moving in filtered light, market-like colors, observation galleries and graceful transport loops.
- Show nature embracing design rather than destroying it: coral and anemones cultivated on selected structures, kelp parks, ray corridors, fish moving through archways and gardens that make the city feel ecologically alive.
#### THE OCEAN AS A MOVING SKY
- The water column must be a masterwork: volumetric sun shafts, drifting particulates, surface shimmer overhead, large slow caustic patterns over city stone, blue atmospheric depth and softly moving shadows when whales or schools cross the light.
- Fill the ecosystem with beautifully staged marine life: the immense hero whale and calf option at distance, manta rays sweeping above plazas, turtles near coral gardens, huge schools of silvery fish turning as one, small reef fish among foreground plants and jellyfish lantern-like drifts in quieter districts.
- Use bubbles and movement as life cues: transit bubble trails, gentle vent streams, residents or divers only where coherent, swaying kelp, fin motion and whale wake pressure suggested through shifting particulate bands.
- Avoid menace, predators attacking, flooding catastrophe or ruined-city sadness. This is the overwhelming wonder of a fully functioning ocean civilization.
#### THE WHALE ABOVE THE CAPITAL
- Make the overhead whale an unforgettable scale anchor, not a decorative silhouette: sculpt a graceful detailed body with subtle skin variation, flippers, tail motion, light rolling over its back and immense shadow passing over towers; keep it high enough for the city to remain the main subject.
- Coordinate the first moment so the whale is already crossing a shaft of sunlight above the central district, with schools parting below and citizens or rays tiny against its scale.
- Include an alternate preset closer to the whale looking down through sunbeams onto Atlantis, making the full city appear even more impossible while preserving tranquility.
#### EXPLORATION, COLOR AND ENGINEERED ABUNDANCE
- Enable immediate orbit, pan and zoom with reset to the city-and-whale hero composition. Presets: grand capital overlook; central dome plaza; coral garden avenue; under-whale view down onto city; outer arch and kelp district; surface-facing panorama through rays.
- Compact controls: sunbeam/water clarity, city activity, marine-life density and architectural illumination mode (sunlit day / glowing twilight depths). Keep the default bright, crystalline and fully readable.
- Reserve handcrafted maximum detail for central palace, foreground terrace, nearby domes, coral plants and hero marine life. Instance repeated city modules, distant lights, mosaic details, schools, kelp and particulates with organic variation.
- Use efficient volumetric approximations, layered caustics, pooled bubble systems and LOD for distant districts. Scale outer-city density, fish counts and volumetric samples before sacrificing whale grace, central architecture or luminous water.
- Clamp devicePixelRatio to 2 and maintain smooth exploration. This world should feel so rich and alive that an impossible myth has become a place the viewer can immediately see, understand and ache to explore.
#### LIVING WORLD SIMULATION - A CITY AND ECOSYSTEM THAT BREATHE
Atlantis must be demonstrated as alive through continuous civic and marine behavior, not merely labelled living by glowing windows and static fish shapes. The opening city-and-whale composition should already contain multiple purposeful flows.
- Give citizens and transport urban routines: residents move within domes and protected plazas, gather briefly at transit nodes, cross bridges and disperse; elegant submersible vehicles follow luminous lanes, dock, release passengers or cargo and depart with evolving bubble trails.
- Make the marine ecosystem autonomous: fish schools turn around architecture and split before rays or the whale shadow, turtles travel between coral gardens, manta rays sweep across plaza light, jellyfish drift on currents and kelp bends in coherent water flow rather than looping randomly.
- Let the hero whale change the city moment: its progress across sunbeams casts an enormous moving shadow; schools part then reform, rays alter paths, particulate bands and caustics change beneath it, and tiny citizens or transports provide astonishing scale.
- Connect districts through signals of function: bubble vents pulse as services operate, windows brighten and dim across occupied routes, cultivated coral gardens are tended and transit activity varies across central and outer neighborhoods.
Use stateful instanced residents, vehicles and schools; flow fields, route rings, docking states and efficient reaction triggers; retain performance through LOD. Every density mode must preserve inhabited behavior. Never settle for frozen silhouettes, identical fish or a city that only glows while nothing meaningfully moves. Prompt collected by petergpt (collection) ; the original author is unknown on GitHub. github.com/petergpt/3d-prompt-collection/blob/HEAD/README.md#prompt-11 . Copies include this credit. 
Sunken Capital Under a Whalepetergpt (collection) · Cities & architecture