Yes, Coco, i saw this article - but there is no source included. And i saw the same
“technique” in an NVIDIA-developer demo.
What you saw in the NVIDIA-developer demo requires a GeForce. The demo I did does not require a GeForce, but it takes 26 passes to achieve its results.
The objects looks like the same, too !
I think, the man, who posted this articel to opengl.org ripped it off the NVidia-demos.
It’s SUPPOSED to look like the nvidia GeForce demo for the very purpose of illustrating that you can do (actually approximate) per-pixel lighting WITHOUT special OpenGL extensions. If you don’t have the fill-rate to support 26 passes, though, it’s gonna crawl. The look of the demo may be “ripped off”, but the technique implementing it is certainly not.
Look at the source for the OIM article that is referenced if you want to understand one way of doing per-pixel lighting in unextended opengl. The technique in the demo is an extension and generalization of that technique.