I've recently started reading up on perspective and have noticed that in just about every tutorial and book i've read all objects in a scene are parallel to each other and so share the same set of vanishing points. In some sites it's been mentioned that objects that don't face the same direction will use their own sets of vanishing points but they dont really go into how to find them. What i'm stuck on (in 2 point perspective) is finding the second VP or more specifically the distance required between them. The second dot point in this link http://www.artlearn.org/courses/Basi...on_Rockman.pdf says that each set of vanishing points just need to have the same distance between them. Can someone confirm if this is acurate? Other sites have alluded to other methods (making sure both angles make up 90 degrees being one) so i'm not sure what to believe.
Hope this makes sense.