Press Release for Air 8.0


December 2008

AIR 8 Introduces Shader-based Procedural Modeling

Denton, Texas - Version 8 of SiTex Graphics' AIR production rendering software introduces shader-based procedural modeling for the efficient creation of large, complex models at render-time. 

AIR 8 has two new shader types for creating objects during rendering:  a procedure shader that populates a bounding volume with new objects on-demand, and an instancer shader type that creates new objects based on properties of a parent object.  AIR 8 ships with a sample procedure shader for growing trees and a companion instancer shader for placing trees that demonstrate the flexibility, control, and efficiency possible with these new shader types.

Procedure shaders:  A procedure shader is defined as a bounding box and an associated shader call.  If AIR encounters the bounding box during rendering, the procedure shader is evaluated to fill the bounding region with new primitives.  Because a procedure shader is written in the same shading language AIR uses for shading and lighting, users can leverage their existing shader-writing knowledge to construct procedural models.  The rich set of shading language pattern-generation functions, including 2D and 3D texture maps and noise functions, can be used to generate new geometry and associated shading information.  The interpreted environment in which procedure shaders execute provides a safe context within which to experiment and to develop procedural models.  Like other AIR shaders, procedure shaders can have an arbitrary set of user-adjustable parameters to control the behavior of the procedural model.

Instancer shaders:  Users attach an instancer shader to a parent primitive and specify a region around the parent within which the instancer will create new objects.  If that region is encountered during rendering, the instancer is invoked to create new objects - just as a procedure shader is evaluated - with the additional ability to sample properties of the parent primitive to which the instancer is attached.  An instancer can query any standard or user-defined data attached to the parent primitive, using a variety of sampling methods, and use that information to define the shading and geometric properties of new objects.

For example, an instancer shader to perform particle instancing is easy to write and to use, with each particle replaced by different geometry for rendering based on per-particle properties.  Because an instancer shader works with the existing method of transferring particle data from a modeler to AIR, the shader author does not need to create a mechanism for accessing the modeler data.  Instancer shaders can be attached to any primitive type, allowing applications beyond simple particle instancing such as converting curves to feathers, growing fur on a mesh, or adding detail geometry to an implicit surface.

AIR 8 includes many other new and enhanced features including 3D texture improvements, updates to the AIR Show framebuffer and Vshade shader creation tool, and a new Massive Agent Light Tool that creates per-agent lights for Massive Software's crowd simulator.

About SiTex Graphics

SiTex Graphics (Denton, Texas) provides advanced rendering software for visual effects, industrial design, architecture, and digital content creation.  SiTex Graphics' products include: AIR, a highly advanced 3D production renderer; BakeAIR, the only standalone dedicated renderer for producing high-quality texture maps; and TweakAIR, a custom rendering engine for tweaking shading and lighting of production scenes.

More information is available on the SiTex Graphics web site:



Scott Iverson

SiTex Graphics, Inc.
804 Sandpiper Drive
Denton, TX 76205
Voice: 206-937-1853


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