@InvalidPointer: thanks for the input, I'll implement a deferred + tiled (cpu) and compare the results in a bigger scene. fortunately it doesn't take much effort to implement a deferred renderer in this engine and compare.
@Guest: sorry but it's been couple of days that I've been busy, I don't know your username on bitbucket, and the problem is bitbucket only allows for 5 developers to have access to private code, and they are full now, I'll remove one of them and give access to u.
thanks again for other users who liked this stuff, I'm currently working in my spare time to make the code public and also make more decent demos.
@Frenetic: there is no reason ?! light prepass may not be the best method for next-gen (dx11+ hardware), but still pretty good for current gen and low/mid-range hardware. especially if you want MSAA too.
About materials, actually you can put all kinds of properties and textures into materials without any fat g-buffers, as for BRDFs I may need couple of them like skin and isotropic which are all applicable for light-prepass.
I'm not making a commercial cutting edge, big epic style engine that can handle huge environments and effects. maybe in the future I implement CS deferred, but not now.