I’ve compiled a very large reference document that is designed to be helpful to BGE users of all skill levels. It is however not specific to the BGE and covers many topics outside of that realm. I’ve put a lot of work into this and I hope it’s helpful. If you’ve ever had a question about how a specific effect is created, from simple animation up to water effects, and parallax occlusion mapping, this document should help you learn the answers. It’s designed to take completely new users and be able to inform them of all the basic steps, as well as people very well versed in the GE - teaching them the graphics pipeline, shaders, and different shading techniques. Hopefully I’ve hit all the bases. Topics included are: Concept art, modeling, unwrapping and texture painting, rigging, object animation, character animation, the graphics pipeline, light mapping, shadow mapping, shadow volumes, and vertex and pixel shaders. Included is a helpful glossary, and everything is fully cited for fact checking and further reading.
http://blenderartists.org/forum/showthread.php?t=128794
http://blender3dtutor.com/index.php?view=article&catid=3%3Agame-developmentplanning&id=19%3Ademystifying-the-art-of-video-games&option=com_content&Itemid=2
Here’s the introduction:
“Every year, millions of video games fly off the shelves of retail stores around the world, and even more are purchased online. In 2007 alone the computer games industry posted a gross profit of $17.94 billion according to the NPD group, a number that far surpasses box-office cinema’s $9.7 billion gross profit (YVG Staff). After purchase, many hours are spent in the games, creating characters, building civilizations, defeating enemies, solving mysteries, and plumbing the depths of archaic dungeons in some distantly imagined world. As these games have progressed and hardware has improved, the experiences offered have become far more visceral and engaging as the artists behind these titles are given the freedom to imagine unique worlds, and they use today’s bleeding edge software and methodology to create them. According to nVIDIA Corporation, “As 3D graphics hardware has evolved over the years, new features have been continuously added resulting in steady improvements to image quality” (Technical brief pixel). Despite the universal appeal of these games, however, as they become more complex, and, more importantly, the processes used to create them become more intricate, the lay audience has less and less knowledge of how they are constructed and how they operate.
Compare this once again to the movie industry. Despite the intricacies of filmmaking, most people who watch movies have at least a fundamental knowledge of how they are made: a camera is used to capture images, usually actors conversing or interacting in some way. It’s common knowledge that a script is followed, and there are stunt men, and intricate lighting, and large set pieces etc. None of this should sound particularly new, and this understanding of the industry leads movie-goers to appreciate particularly good films. On the other hand, most people don’t know how the character they play in a video game is created, nor do they understand how the water in the game flows, or how the light reflects off windows, or even how the doors of the houses swing open. Does anyone outside of the industry understand what UV texturing is? Or could perhaps define a shader? This lack of awareness of the industry is understandable; the concepts behind game development are far less tangible than that of film making, but this ignorance is worrisome when compared to other artistic entertainment mediums. This lack of transparency is a problem because if no one understands the process that games endure from the conceptual phase to become the sometimes breathtaking products that grace retail shelves, then it is easy to dismiss them as some cheap, easy to create market fad. The lack of appreciation is damaging to the reputation and understanding of the gaming community as a whole and severely inhibits its progression as an art form. The artists within the industry need to take the initiative to promote the understanding of the art form just as the audience needs to be responsible for the absorption of this knowledge. The following is intended as a step in that direction by promoting education of the subject.”
If anyone finds any factual errors, please let me know so I can make immediate corrections.
Thanks again to Jason Lin for hosting and formatting this considerable piece of text.
(And yes there are pictures, so it’s not too dry…)

