problems with enabling the polygon smooth

When i enable the polygon smooth, i see a line in my polygons :eek: What’s the problem?

Do you use glHint (GL_POLYGON_SMOOTH_HINT) ?

You must draw from front to behind, use blending with GL_SRC_ALPHA_SATURATE.

This is the only way I know, maybe there is something about multipasses, either I don’t know.