Letter-shaped city skyline prompt using signed distance fields

INPUT: $ LETTER, $ CITY_STYLE // Define a 3D signed distance field for the target letterform. Φ(x,y,z) = letter_sdf($ LETTER) // negative inside the letter shape // City morphology: generate building placement via a 3D Poisson‐disc sampling constrained to the interior (Φ < 0). // Each building’s height, style, and roof type are inferred from $ CITY_STYLE (e.g., Haussmann → mansard roofs, wrought‐iron balconies). F = -∇Φ // structural grid follows the gradient, creating street canyons along the letter’s strokes Curl = ∇×Φ // curves in the letter (bowl of P, R, B) become sweeping boulevards // Apply material physics: Haussmann stone, neon signs for Tokyo, red brick for London, etc. // Lighting: infer from city (golden hour for Paris, neon night for Tokyo, misty morning for London). // Camera: isometric, telephoto 200mm equivalent, f/8, miniaturized tilt‐shift effect. // Detail: windows, cornices, balconies generated by rule‐based subdivision of building surfaces. Render 8K, Unreal Engine 5 quality, micro‐detail on every facade.