Direct3D Microsoft's Direct3D is part of the larger DirectX standard that takes away one of the great burdens of 3D software development: addressing display hardware efficiently. Direct3D is a type of API called a hardware abstraction layer that stands between the application and the hardware that will display it. The developers of the software (usually a game) write instructions to Direct3D, which then translates them to the graphics card. To take advantage of the API, therefore, both the application and the graphics card must support Direct3D. See also: API, DirectX, hardware abstraction layer