Make a line drawing of a building or several buildings seen corner-on. Use every possible vertical or horizontal reference to ensure that receding lines are drawn at the correct angles.
When you have drawn the building as accurately as possible draw in your eye level and extend receding lines to it. All in-life parallel lines should meet on your eye level but there will be many different vanishing points. mostly off your paper.
I chose to draw our local pub The Old Plough on location. It was a bit of a mistake as it is a very old building and very few of the angles appeared to be right-angles and its lines not particularly sleek. It also is situated on a hill so that the furthest part of the building from where I was standing was higher. I should have chosen a nice sleek-lined modern building, it would have been much easier. However I persevered. I drew in black pen on A3 paper (also a mistake as this was hard to handle out-of-doors – too big to hold properly and no time to set up an easel).
What threw me was that the base line of the building was not in fact parallel with gutter line or the roof ridge. Back home I drew in the perspective lines, extending onto paper extensions to the sides. This is not a good photo but I include it here so you can see what I did.
The lines are all over the place basically! There certainly are lots of vanishing points, but very few of the in-life parallel lines appear to be heading to meet at the eye line (even though these will be off the page extensions).
I tried the different exercise of drawing a pile of books.
I was looking down onto this pile so my eye line was above the drawing and rather stupidly I hadn’t accounted for drawing this in when I drew the sketch. I drew in the perspective lines (using a different colour for each book). Although I couldn’t tell if the correct pairs of lines were meeting at the horizontal, I could tell if they were converging, parallel or even diverging.
As you can see one set of lines were in parallel on my drawing (light blue) and two sets were actually diverging (albeit by small amounts but diverging never-the-less!).
Although these exercises were quite messy I did learn a lot from drawing in the lines. I would hope that I will be able to use this experience to improve my drawing. I was curious as to how a sketch I had done of boxes right at the beginning of the course would stand up to such angular perspective scrutiny. I photocopied the sketch and repeated the process of putting on the receding perspective lines. Once again I could not trace back to the vanishing point, however the results were quite revealing! The top surface of the top box was in fact diverging as was the left hand side of the long rectangular box in the foreground (blue lines not labelled).