Drawing Silhouette Edges

With SIGGRAPH, the release of ShaderX^2 for free, and the publication of our own 3rd edition, there was much to report, but now things have settled down a bit. The bread and butter content of this blog is any new or noteworthy article or demo that is related to the field. The assumption is that not everyone is tracking all sources of information all the time.

So, if you don’t subscribe to Gamasutra’s free email newsletters, you wouldn’t know of this article: Inking the Cube: Edge Detection with Direct3D 10. It walks through the details of creating geometry for silhouette and crease edges using the geometry shader. To its credit, it also shows the problem with the basic approach: separate silhouette edges can have noticeable join and endcap gaps. One article that addresses this problem:

McGuire, Morgan, and John F. Hughes, “Hardware-Determined Feature Edges,” The 3rd International Symposium on Non-Photorealistic Animation and Rendering (NPAR 2004), pp. 35–47, June 2004.

One minor flaw in the Gamasutra article: the URL to Sarah Tariq’s presentation is broken (I’m writing Gamasutra to ask them to correct it), that article is here.

Tags: , ,