Edge Detection with Direct3D 10 With Geometry Shaders
Here is tutorial that shows how to do edge detection for non-photorealistic rendering (NPR). Edge detection is also useful for gpu accelerated shadow-volumes. The author uses Direct3D 10′s geometry shaders to provide a GPU-based implementation of edge detection.
Read the complete tutorial here: Sponsored Feature: Inking the Cube: Edge Detection with Direct3D 10.