Well I was experimenting some of Lightning's grass models then I realized this strange effect before the grass pass. It rendered first then the grass. Could it be the ground in shadow (but it's strange, like reflecting the sky)???
What is it??? Water?? There isn't any water shader in the scene... ???
Is this a known bug?? Does it lower the render process???
Looks like the ground in shadow, which is usual to see when rendering large populations. Reduce the population count to a fifth if you really want to check it.
ok, I'm trying it right now...
Geez, thank God you were right!!!!
It was just the shadowed ground!!!
I know, I know, have to verify things before posting!!! ;D