This was an exercise to see how accurate my guess work was when it came to estimating perspective. A simple task to use all the reference points I could to construct a building without drawing in the vanishing points or perspective lines until after the drawing was finished.
I chose a simple three story building which had a flat corner receding off into two point perspective. I positioned myself so the corner was directly in front and lined up two other buildings to the left and behind the main one.
My guess work for the front building was actually quite accurate, having four stories of repeating windows to help me line up and a set of 4 trees in the foreground also helped me gauge the depth of field. What through me off was the building to the left. Although it was sitting flush with the main building, it appeared to sit in front of it.
I was surprised to find that they both shared the same vanishing point, however, to throw me off the tracks even more there was a section of windows jutting out from the side of the building that was on a completely different angle to the main building, forming a sort of triangle that had a new vanishing point altogether! Not only this, but the side of the building itself was not sat flush with the main building, so I found myself tackling three different sets of vanishing points!
At this point I really had to look closely at the relationship of the angles of the buildings and almost guess where to place the lines, simply using my judgement of eye to see if I was right or wrong.
After drawing in the lines on returning home I was however pleasantly surprised to find how many lines I had been able to keep intact, but the exercise taught me a good deal about how important cross referencing is, helping me to look closer at details of the buildings in relation with one another as well as simplifying the buildings down into lines before filling in the detail.
Unfortunately when I was filling the lines in at home I used a paint pen that leaked red ink over the drawing and I didn’t manage to get a photo before the accident!