Underwater aquarium tunnel at midday, visitors walking through massive curved glass passage surrounded by tropical fish and coral reefs, volumetric sun rays filtering through water creating god rays and dancing light caustics on curved walls, hand-painted aesthetic with visible brushstrokes, watercolor texture, frame-by-frame animation quality, Unreal Engine 5 render with raytracing and global illumination, volumetric lighting, subtle paper grain, meditative wonder mood, soft ambient occlusion, PBR materials, cinematic composition with strong leading lines toward distant underwater view