This example shows the difference of where the horizon, and therefore the vanishing points in two-point perspective makes. The original frame for each of these examples was a 1500x1500 pixel Photoshop document. The two figures in each of the examples is exactly the same.
The figure on the left had a center vertical at x = 300, beginning at y = 600 and ending at y = 1000. The left edge was drawn at x = 200 and the right edge at x = 400.
The figure on the right had a certer vertical at x=1000, beginning at y = 600 and ending at y = 1000. The left edge was drawn at x = 750 and the right edge at x = 1250.
The top pair of figures was drawn with the horizon at y = 1250, which is 4/5 of the way down the frame. The vanishing points were at x = 100 and x = 1400.
The middle pair of figures was drawn with the horizon at y = 850, which is 1/2 way down the frame. The vanishing points were the same as above, 100 and 1400.
The bottom pair of figures was drawn with the horizon at y = 150, which is 1/5 of the way down the frame. Vanishing points were as above. The addition of windows and a door to the figure on the right was done just to hone my perspective skills and because I could.
