In the last version of After Effects CS6, there are many interesting features. 3d ray tracing is a new rendering engine inside of After Effects, and it is a mode to render your levels inside a specific composition.
What could be done with 3d ray tracing enable for a composition?
You could extrude your shape layers (even those who are converted from a vectorial source), solids, texts and some other features, like reflections, environments, environment layers. All this very nice features are brought to you to enhance the possibilities of After Effects and your creativity.
The real power behind is the possibility to use the GPU instead of the CPU, using CUDA cores with huge impacts in render times. You could check in this page about the features of the GPU inside After Effects CS6.
But if I don't have an official supported video-card? How could I use GPU?