One of the most important and the biggest changes of the last release (Maya 2012) was Viewport 2.0. I want to take this opportunity to provide you some additional information on the new Viewport 2.0 API. Previously in Maya if you had several high polygon models and you were trying to manipulate those models, Maya sometimes could behave slowly.
Viewport 2.0 is a brand new rendering system it is based on an internal technology by Autodesk. By using this new architecture, we are trying to replace all the old rendering system. As you can see this is a fundamental architecture change. The purpose of the change is to have high performance when rendering large complicated scenes. Viewport 2.0 is much faster compared to the old viewport. Keep in mind when importing this new technology, we have dramatically changed the way shading and rendering works in Maya.
Viewport 2.0 provides a programmable shader system allowing you more flexibility with customization. You can customize a shape, a shader, or a rendering process; it’s all possible with this new system. This new rendering system includes a new viewport 2.0, but also includes a batch version called Hardwar Renderer 2.0. In Maya 2012 there are a lot of new classes in the API. Since some of the new classes have the same name as the old classes, the new classes are in a new namespace called MHWRender.