When we render elements ,such as a triangle,there're some pixels's alpha are zero..
And I need to change some data value such as stencil value of this pixel when the alpha is not zero..But how..
As we know glStencilOp allow us to change the stencil value by depth test and stencil test but we can do nothing about "alpha test"..
I've think about to create another buffer to instead stencil buffer ..But still I can't find any way to change the data by "alpha test"...
No matter with FBO,MRT and GLSL I have no idea about it ..
Any one knows it ?