Sun Beams node. Where do the rays come from? Creating Sun Rays is always a struggle. 
Today, I am trying to create rays coming from below around silhouettes produced with transparent PNGs - reusing several tips I found on here.

And it seems that the rays are going down rather than up...



In this setup, the light comes from an emission plane, above which are silhouettes.



The World Compositing setup.



The Volumetric environment.



Unfortunately, when I render the rays seem to come from above and mask part of the silhouettes! On this render, it is obvious that the emission is way below the silhouettes.

How do I make the rays come from the Emission object?
Sun beams node works with normalized screen space coordinates, where (X0.5; Y0.5) is the Camera's midpoint.



Your current point (X0.7; Y1.1) is way out of the screen. Try something like (X0.5; Y0.25) - it will be lower part of the screen, where is light coming from.