Code:

material right_alpha_mat
{
effect =
"
technique right_alpha1
{
pass p0 {zWriteEnable=true; alphaTestEnable=true;}
}
";
}


action right_alpha_acc
{
my.material = right_alpha_mat;
}



http://www.coniserver.net/wiki/index.php/ImprovedOverlay


no science involved