Applying drywall around a 3D chimney involves careful measurement and precision. Start by measuring and cutting drywall panels to fit the chimney’s dimensions, ensuring a snug fit around edges and corners. Secure the panels using screws or nails, and reinforce external corners with metal or plastic corner beads. Apply joint tape along seams and cover with joint compound, feathering the edges for a smooth finish. Once the compound is dry, sand the surface to eliminate imperfections. Finally, prime and paint or texture the drywall to seamlessly integrate the chimney with the surrounding walls.