Quote:
|
How did you place the two vanishing points ? Did you measure them to the right place or how?
|
Allan,
You are astute to ask this question. In fact, in my quick sketch, I just located the vanishing points where it was convenient to do so. More correctly, one would have to establish a so-called "circle of view", the radius of which is the distance from the viewer to the image plane (or drawing). From any point, then, on that circle, the vanishing points would be 90 degrees apart (using the point on the circle as the vertex of that angle.) This gives you an infinite number of available perspectives, though a relatively small number of them will produce aesthetically pleasing results, which for our purposes here is the primary consideration.
A caveat, that this is the procedure for the cubic polyhedron. Other forms require modification of this approach.
All of which is why I suggested that Ken focus on what he could see, with an eye to aesthetic considerations, rather than worry about precision in perspective.