Can i do like this :
1, Rendering all opacity objs.
2, Sorting all transparent objs, then rendering them by 2 pass:
a, pass 1:
Disable alpha blend, enable alpha test, enable zBuffer, enable zBuffer-writable, only rending the pixel with alpha>=1(means 100% opacity ).
b, pass 2:
Enable alpha blend, enable alpha test, enable zBuffer, disable zBuffer-writable, only rending the pixel with alpha<1