Direct3D

[6] Integration with other DirectX technologies enables Direct3D to deliver such features as video mapping, hardware 3D rendering in 2D overlay planes, and even sprites, providing the use of 2D and 3D graphics in interactive media ties.

The API does include a Reference Rasterizer (or REF device), which emulates a generic graphics card in software, although it is too slow for most real-time 3D applications and is typically only used for debugging.

[8] As part of DirectX, Direct3D is available for Windows 95 and above, and is the base for the vector graphics API on the different versions of Xbox console systems.

[16] Microsoft bought RenderMorphics in February 1995, bringing its staff on board to implement a 3D graphics engine for Windows 95.

For DirectX 2.0 and 3.0, the Direct3D immediate mode used an "execute buffer" programming model that Microsoft hoped hardware vendors would support directly.

[22] Besides introducing an easier-to-use immediate mode API, DirectX 5.0 added the SetRenderTarget method that enabled Direct3D devices to write their graphical output to a variety of DirectDraw surfaces.

[23] DirectX 6.0 (released in August, 1998) introduced numerous features to cover contemporary hardware (such as multitexture[24] and stencil buffers) as well as optimized geometry pipelines for x87, SSE and 3DNow!

DirectX 8.0 (released in November, 2000) introduced programmability in the form of vertex and pixel shaders, enabling developers to write code without worrying about superfluous hardware state.

Direct3D 8.0 and its programmable shading capabilities were the first major departure from an OpenGL-style fixed-function architecture, where drawing is controlled by a complicated state machine.

[31][32] Direct3D subsumed all remaining DirectDraw API calls still needed for application development, such as Present(), the function used to display rendering results.

[43] Unlike prior versions of the API, Direct3D 10 no longer uses "capability bits" (or "caps") to indicate which features are supported on a given graphics device.

Because Direct3D 10 hardware was comparatively rare after the initial release of Windows Vista and because of the massive install base of non-Direct3D 10 compatible graphics cards, the first Direct3D 10-compatible games still provide Direct3D 9 render paths.

[44] Direct3D 10.0 level hardware must support the following features: the ability to process entire primitives in the new geometry-shader stage, the ability to output pipeline-generated vertex data to memory using the stream-output stage, multisampled alpha-to-coverage support, readback of a depth/stencil surface or a multisampled resource once it is no longer bound as a render target, full HLSL integration – all Direct3D 10 shaders are written in HLSL and implemented with the common-shader core, integer and bitwise shader operations, organization of pipeline state into 5 immutable state objects, organization of shader constants into constant buffers, increased number of render targets, textures, and samplers, no shader length limit, new resource types and resource formats,[45] layered runtime/API layers,[46] option to perform per-primitive material swapping and setup using a geometry shader, increased generalization of resource access using a view, removed legacy hardware capability bits (caps).

The specification was finalized with the release of November 2007 DirectX SDK and the runtime was shipped with the Windows Vista SP1, which is available since mid-March 2008.

Direct3D 10.1 level hardware must support the following features: Multisampling has been enhanced to generalize coverage based transparency and make multisampling work more effectively with multi-pass rendering, better culling behavior – Zero-area faces are automatically culled; this affects wireframe rendering only, independent blend modes per render target, new sample-frequency pixel shader execution with primitive rasterization, increased pipeline stage bandwidth, both color and depth/stencil MSAA surfaces can now be used with CopyResource as either a source or destination, MultisampleEnable only affects line rasterization (points and triangles are unaffected), and is used to choose a line drawing algorithm.

Direct3D 11.1 includes new feature level 11_1, which brings minor updates to the shader language, such as larger constant buffers and optional double-precision instructions, as well as improved blending modes and mandatory support for 16-bit color formats to improve the performance of entry-level GPUs such as Intel HD Graphics.

[112] Direct3D 12[114] allows a lower level of hardware abstraction than earlier versions, enabling future applications to significantly improve multithreaded scaling and decrease CPU utilization.

[114] In the words of its lead developer Max McMullen, the main goal of Direct3D 12 is to achieve "console-level efficiency" and improved CPU parallelism.

[115][116][117] Although Nvidia has announced broad support for Direct3D 12, they were also somewhat reserved about the universal appeal of the new API, noting that while game engine developers may be enthusiastic about directly managing GPU resources from their application code, "a lot of [other] folks wouldn't" be happy to have to do that.

[118] Some new hardware features are also in Direct3D 12,[110][119][120] including Shader Model 5.1,[121] Volume Tiled Resources(Tier 2),[121] Shader Specified Stencil Reference Value, Typed UAV Load, Conservative Rasterization(Tier 1), better collision and culling with Conservative Rasterization, Rasterizer Ordered Views (ROVs), Standard Swizzles, Default Texture Mapping, Swap Chains, swizzled resources and compressed resources,[122] additional blend modes,[123] programmable blend and efficient order-independent transparency (OIT) with pixel ordered UAV.

While resource binding is fairly convenient in Direct3D 11 for developers at the moment, its inefficiency means several modern hardware capabilities are being drastically underused.

When a game engine needed resources in DX11, it had to draw the data from scratch every time, meaning repeat processes and unnecessary uses.

It provides a low-level interface to every video card 3D function (transformations, clipping, lighting, materials, textures, depth buffering and so on).

Each resource has four attributes: Direct3D implements two display modes: The Microsoft Direct3D 11 API defines a process to convert a group of vertices, textures, buffers, and state into an image on the screen.

Support for individual features had to be determined using "capability bits" or "caps", making cross-vendor graphics programming a complex task.

[67] More advanced features in a major revision of the Direct3D API such as new shader models and rendering stages are only exposed on up-level hardware.

[162][163] WDDM driver model in Windows Vista and higher supports arbitrarily large number of execution contexts (or threads) in hardware or in software.

[86] This overcomes a potential scheduling problem when application would have very long execution of a single command/batch of commands and will have to be terminated by the OS watchdog timer.

They are useful for non-Windows platforms and for hardware without some versions of DX support: Direct3D comes with D3DX, a library of tools designed to perform common mathematical calculations on vectors, matrices and colors, calculating look-at and projection matrices, spline interpolations, and several more complicated tasks, such as compiling or assembling shaders used for 3D graphic programming, compressed skeletal animation storage and matrix stacks.

[180] Some features present in previous versions of D3DX were removed in Direct3D 11 and now provided as separate sources:[181] DXUT (also called the sample framework) is a layer built on top of the Direct3D API.