glColor4f() - effect of alpha value

Question

I am using glColor4f(). Surprisingly, changing the alpha, i.e., the fourth argument doesn\'t cause any change in transparency. The code segment is:

const GLfloat         


        

Answer 1

You need to enable blending if you want to use transparency:

glEnable(GL_BLEND);

See also glBlendFunc to setup the blending function.