HOW TO DRAW THE OBLIQUE PERSPECTIVE AND THE PARALLEL PERSPECTIVE SIMULTANEOUSLY, INSIDE THE SAME VISUAL SPACE, WITH A SINGLE VIEW POINT
Construct the environment in parallel perspective, placing the distance, horizon and support lines to scale as previously explained.
Find the oblique perspective points: vanishing points 1 and 2, measurement points, depth point and mark also the vanishing and depth points of the parallel perspective.
See figure nº 42 where a plane in squares in oblique perspective is shown, developed inside a space in parallel perspective.
The line perpendicular to the horizon marks the vanishing point of the parallel perspective, the view point and the respective centers of the squares: of the vertical square and of the square on shortening scale (scorcio). Find this perpendicular line by drawing the vertical square and finding its perspective center by the diagonals that join their vertices.