"Craft a visually stunning 3D polka dot pattern for a black material, incorporating mixed sizes for added beauty. Generate a design that captivates with its depth and dimension, showcasing the elegance of the black backdrop. Play with various dot sizes, ensuring a harmonious yet dynamic composition. Emphasize the beauty of the polka dots in 3D, aiming for a pattern that is both playful and sophisticated. The final result should be a captivating material pattern, perfect for creating a stylish and visually appealing piece with a mix of charm and modernity."