Study of an architecturally composition

I have an picture taken from the campus of the University of Toronto in the past. It was taken during a walk in August 2016 during one of those vacations back home by my elder son during his Med School. Good days, that I still remember spending with him waking the downtown.

This is my reference picture

In my study, I have tried to capture the outlines of the composition in 3 point perspective and mark the shades as well as the most important features that I will paint next.

Note how the central point of the picture as well as the drawing is the gate at the end of the pathway taken by the three humanly shapes.