Ultimate XAML,
J Collins Design
August - 2009

Ultimate XAML for Softimage is a plugin for Autodesk Softimage and Mod Tool that helps with the creation of 3D XAML content. The primary audience includes user interface developers of XBAPs (such as web games) and standalone applications. It is more than just a simple exporter; it includes a real time shader that mimics how XAML content appears in a Windows Presentation Foundation (WPF) application so that the final model can be accurately visualized during creation. The WPF shader settings correspond exactly to the settings available to the XAML material settings so there is nothing lost in translation. Other exporters we’ve looked at impose severe limitations on the types of materials they can generate or the composition of the scene; we’ve done our best to minimize these limitations and make this process as simple as possible. Scenes can have arbitrary hierarchies, objects can have local transforms, meshes can have subdivision surfaces and even instances are fully supported in the final XAML to keep file sizes down.
The plugin also includes the Ultimapper Helper which is designed to help create the image maps XAML requires, which I’ll explain more about later.
Another aspect of this plugin is the ability to create C# code that helps interface programmers use the exported objects within an application and integrate the resources with the project in a type safe manner. The main benefit of this is the compiler will produce errors if an asset that doesn’t exist is referenced by the code.
While this is the first public release of Ultimate XAML for Softimage, we initially created this tool in 2006 to solve our own development needs while creating XBAP games and other applications and we have been slowly improving it since then. We would very much like to start seeing Windows applications incorporate 3D elements more often because we think it can make for a better user experience. Not too long ago we decided to make it available to others because clearly, even though 3D XAML has been available to developers for several years now, it is not used very much. We hope this tool makes it a little easier for developers to make slick looking and fun to use applications.

XAML is the standard way to integrate 3D content into the user interface a Windows Presentation Foundation application. Historically, applications that needed to present 3D content would use either pre-rendered bitmaps or Direct 3D. Pre-rendered bitmaps certainly continues to have its place in UI design but does have some obvious limitations in that dynamic 3D content isn’t an option. Integration with Direct 3D poses many implementation challenges because embedding a Direct 3D rendering system within a user interface without it becoming the user interface is very complicated. Certainly possible, but not as convenient as using XAML which enables the user interface programmer to simply embed a 3D control into the middle of an existing user interface. Any Windows PC that has .NET 3.0 or greater (which is included in all Windows Vista and Windows 7 installations and can be installed onto XP) can embed 3D XAML content directly into the user interface of an application. 3D XAML content coexists with all other user interface systems of the Windows Presentation Foundation, and 3D XAML appears the same way across all supporting systems with no special hardware requirements. Microsoft has made significant investments in making 3D XAML available as a component for designing user interfaces, but we only rarely see it used partly because of the difficulties in creating content in that format. This tool is designed to help solve that problem.

The basic requirement is to create a collection of meshes which have render trees configured to use the WPF real time shader included in the plugin. The render trees can be shared or unique per mesh. The shader provides precise control of the settings of the XAML materials that are emitted by the exporter. Each render tree can have any number of WPF shaders chained together, and the exporter will produce a XAML Material Group that corresponds to how these are connected. This allows XAML objects to be constructed which use any combination of diffuse, specular and emissive materials. These are distinct material types in XAML and the WPF shaders can be configured individually to suit the artists preferences for each material in use. If the creation of a model requires the use of Mental Ray shaders, as is often the case, the images need to be baked into image files for use with the WPF shaders. This is a task very similar to game developers reducing a high resolution model into a game-ready model. The Ultimapper Helper can make that process easier by coordinating the generation of these images across multiple instances of Ultimapper objects, one per material channel.