Geometric Tools

I think its a big help, many articles and source code for a Graphics Engine

http://www.geometrictools.com/index.html

This is the official site for the Wild Magic Real-Time 3D Graphics Engine, version 4, whose design and architecture is described in the book, 3D Game Engine Design: A Practical Approach to Real-Time Computer Graphics, 2nd edition (3DGED2), a book in The Morgan Kaufmann Series in Interactive 3D Technology. The book focuses on the details of constructing a scene graph management and rendering system for shader programming. The Wild Magic version 4.0 engine is on the book’s companion CDROM. It illustrates the ideas in the book yet is ready to use for commercial as well as noncommercial applications. All in all, we believe you will discover that this source code really is magic software!

The current version of the Wild Magic engine is 4.9. The source code update for the engine is accessible at the Downloads page and was posted on April 11, 2009. Much of the source code is for 3D real-time graphics, but you will find quite a bit for other purposes. The update history for bug fixes and new features is maintained here. Known problems that require our attention but are not yet fixed are also listed at the Downloads page.