What's New in the April 2006 DirectX SDK

The following features have changed in the April 2006 DirectX SDK update:

Direct3D 10 Technology Preview
Windows Vista Game Explorer (Beta)
XInput
Microsoft Cross-Platform Audio Creation Tool (XACT)
Tools
Technical Article Updates

Direct3D 10 Technology Preview

The Direct3D 10 Technology Preview showcases the newest set of graphics API's for games and other high-performance multimedia applications on next-generation graphics hardware. This technology preview provides reference material, conceptual content, developer libraries, tutorials and samples that demonstrate how to use Direct3D 10. Additional content will provided in upcoming SDK releases.

Samples and applications built with the Direct3D 10 Technology Preview in the April 2006 DirectX SDK require the Windows Vista February 2006 CTP to run. The Windows Vista February 2006 CTP is available to MSDN subscribers.

The D3D10 libraries in the April 2006 DirectX SDK (Reference Rasterizer, Debug Layer, D3DX10) are unchanged from the Direct3D 10 February 2006 Tech Preview Update in the February 2006 DirectX SDK. New samples have been added in this release. Developers can expect a series of changes to arrive in subsequent SDK's.

For known limitations of this Technology Preview, refer to the Microsoft DirectX SDK ReadMe.

This documentation set is intended for developers using the C/C++ programming language.

HLSL Shader Compilation

In the Direct3D10 February 2006 Tech Preview, a preview version of the new HLSL compiler targeting downlevel (Direct3D9) shader models was included. The compiler preview has been updated this SDK with a series of shader-code-generation improvements.

Using FXC10.exe included in this SDK, you can try out the new HLSL compiler (with new language features such as Improved Flow Control Management) on Shader Model 3.0 and below. Keep in mind that not all HLSL optimizations and new features are active in this release. Generated shaders will not be fully optimized.

Samples

A new sample illustrating displacement mapping on dynamic objects using geometry-shader prism extrusion and pixel-shader raytracing has been added. This technique adds significantly more surface and silhouette detail to an object, and is scalable across levels-of-detail.

A new sample illustrating multi-stream rendering has been added. This sample supports both Direct3D 9 and Direct3D 10. The Direct3D 10 version also illustrates multi-stream rendering with multiple index buffers.

General Information

For more information on the Direct3D10 April 2006 Technology Preview, see the Direct3D 10 documentation. For known limitations of this Technology Preview, refer to the Microsoft DirectX SDK ReadMe.

To access the Direct3D 10 documentation, click the Start Menu, choose All Programs, Microsoft DirectX SDK (April 2006), and select "Documentation for Direct3D 10". To access the ReadMe, click the Start Menu, choose All Programs, Microsoft DirectX SDK (April 2006), and select "Microsoft DirectX SDK ReadMe".

Windows Vista Game Explorer (Beta)

The Windows Vista Game Explorer documentation has been updated for April with new information about using the Game Definition File Editor.

To access the Game Explorer documentation, click the Start Menu, choose All Programs, Microsoft DirectX SDK (April 2006), and select "Documentation for Game Explorer".

XInput

The XInput API has been updated with the following features for this release:

Support for arcade sticks and wheel controls through subtypes.
A new function, XInputEnable, which can activate or deactivate XInput processing to respond to focus change events.

Additionally, the name of the XInput DLL has been changed to XInput1_1.dll.

Microsoft Cross-Platform Audio Creation Tool (XACT)

XACT has been updated for April with the following new feature:

The IXACTSoundBank::Prepare and IXACTSoundBank::Play methods of the IXACTSoundBank interface have been updated to support seeking to a specified time offset for playback.

Tools

PIX

Texture/Surface viewing support has been improved.

Use the texture viewer to select which mip level/face/texture to view
View image channels separately or together using the channel(s) combo box
Adjust image brightness and contrast, and see high-dynamic range image information using the channel levels control
The depth and stencil channels are viewed via the Render tab, or by viewing depth/stencil surfaces directly

Vertex/Index Buffer Viewing Support

The contents of vertex buffers and index buffers can now be displayed, using a user-specifiable format

Improved Direct3D10 support

ID3D10Device state can be viewed
ID3D10StateBlock contents can be viewed
ID3D10Buffer contents can be viewed
ID3D10Texture contents can be viewed in more ways

D3DX9 Improved UVAtlas Partitioning Algorithm

In this version of D3DX9, the UVAtlas partitioning algorithm has been significantly improved to produce better results (including fewer charts) for a given stretch threshold.

For example, using the mesh: Samples\Media\MicroscopeCity\occcity.x, the comparative results with the Feb SDK are as follows:

Stretch Threshold	Number of Charts (Feb 2006 SDK)	Number of Charts (April 2006 SDK)
0.3	228	194
0.166667	403	363
0.01	1880	1109

D3DX9 February 2006 SDK	D3DX9 April 2006 SDK

The new algorithm in April is more computationally intensive, so the UVAtlas API's will revert to the previous algorithm for input meshes with more than 25,000 faces. The new algorithm also does not support signal specialized parameterization, so if IMT is specified, the old algorithm is always used.

Additional user control over performance vs. quality, as well as support for signal-specialized parameterization, is planned for a future release.

Technical Article Updates

A variety of new articles have been added to the SDK: