Pixar just open sourced their famous Catmull-Clark Subdivision Method created back in 1978 by Ed Catmull (Now President of Pixar Animation Studios) and Jim Clark (Founder of SGI and Netscape).
1998, Tony DeRose (Director of R&D at Pixar) added a method to define crease values on edges and vertices to allow hard edges on a smooth surface. This algorithm revolutionized the way of 3D modeling over the last decade, replacing NURBS.
The 1978 basic-method was freely available but the creasing and other methods were patented and only available through licensing. Instead of licensing major 3D Software companies produced their own solution to creasing. That was fine until now. Nowadays 3D-Data needs to be transferred between different 3D Packages, leading to massive incompatibilities when it comes to subdivision models and their creasing values. Artifacts occur and the only frustrating solution is to remodel the 3D-Data to match the host application.
With Siggraph 2012 Pixar released the whole Subdivision Code for free! This means all 3D-Software developers can now implement the code into their product and we may be able to move our assets between any of the actual 3D-packages.
A big thanks to Pixar for that!
Get the Source and more Infos here
Quote from the Readme at Github:
OpenSubdiv is a set of open source libraries that implement high performance subdivision surface (subdiv) evaluation on massively parallel CPU and GPU architectures. This codepath is optimized for drawing deforming subdivs with static topology at interactive framerates. The resulting limit surface matches Pixar’s Renderman to numerical precision.
OpenSubdiv is covered by the Microsoft Public License, and is free to use for commercial or non-commercial use. This is the same code that Pixar uses internally for animated film production. Our intent is to encourage high performance accurate subdiv drawing by giving away the "good stuff".
OpenSubdiv is entering open beta for SIGGRAPH 2012. Feel free to use it and let us know what you think.
For more details about OpenSubdiv, see Pixar Graphics Technologies.
Note that this beta code is live and will undergo significant churn as it approaches release. Expect that APIs will change as the code is continually improved.