I've just enabled back face culling and noticing a weird behavior: when all vertices of my triangle is outside the view and 2 of them is behind me (I think) the triangle disappears.

So to imagine it: when I'm floating the blue cube like this:

![Before disappearing][1]

If I move closer the corner so all vertices out of the view, two triangles suddenly disappear:

![After disappearing][2]

I suspect the projection matrix reverses the order of the two vertices when they fall behind me, and changes the winding of my triangle.

But it's unclear why does the triangles disappear only if all vertices out of view...

How can I work around this problem, if possible?


 [1]: https://i.sstatic.net/GPDKo.png
 [2]: https://i.sstatic.net/Hmajs.png