Which main-series Pokémon games were the first rendered entirely in 3D?

Pokémon X and Y were the first main-series Pokémon games rendered entirely in 3D.

Released worldwide for the Nintendo 3DS in 2013, Pokémon X and Y moved the core role-playing series away from the primarily sprite-based presentation used in earlier generations. Characters, environments, battles, and Pokémon models were presented in three-dimensional graphics.

The games introduced the Kalos region, which is inspired by France, and added the Fairy type, Mega Evolution, and character customization. Their simultaneous worldwide release was also a major change for the main series.

Earlier Pokémon games used limited 3D elements, especially on systems such as the Nintendo DS, but they were not fully 3D throughout. Pokémon X and Y are therefore distinguished from games that merely included isolated three-dimensional scenes.