Posted by archidrawing on January 14, 2011
This perspective represents a frontal view of some row houses. Seemingly, this is a one-point perspective drawing, but you can observe how the roof lines go to another vanishing point, and not to the one visible on the horizon line. This point helped drawing the direction of the roof’s shingle. It can be found by constructing the perspective lines of the roof’s margins and elongating them until they intersect, and where they intersect is the second vanishing point. This point must be on the same vertical as the first vanishing point established when I have started the drawing. So we can talk about a main vertical line where we can place as many vanishing points as we need to describe all the different plans that we have in this kind of drawings (two parallel plans use the same vanishing point). The reason the point appears is that the roof’s plan is not vertical and if the windows on the wall have horizontal and vertical lines only, the shingle’s lines must converge to that vanishing point. It’s like taking the wall’s plan and rotate it toward the observer. If the roof had some skylights (and we wanted a detailed, built perspective), we were facing the third vanishing point where the lines of the skylight’s thickness (visible at the skylight’s corners) converge. This third point will also be situated on the same vertical line with the other two vanishing points. We can consider the frontal plan having a vanishing point placed at infinity, therefor the vertical lines in this plan are parallel in perspective and perpendicular on the horizon line. Note that the horizontal lines in both roof and wall plans must be parallel with the main horizon line.