the 60" height, although not at the scale of the ground line, unless it extends from the horizon to the ground line. The importance of scaling the drawing can be seen by examining a drawing that does not consider scale accurately. The student drawing of a setting is in error because the chairs and doors are not scaled correctly. When correctly drawn, based on an underdrawing of 30" cubes, it is apparent that the space is too small to accommodate the proposed furnishings. The scale of the objects is as important as the perspective structure itself. 0°_90° The depth of a cube is drawn using the 45° VP. (This is the Alberti, distance-point method.) Depth Measurement of Cubes on Each of Four Axes 0°_90° Draw a 30" square. The diagonal to the 45° VP measures the depth. (This is the same construction as the distance point method described in most texts.) 45°-45° Draw a 30" square with a diagonal and rotate the diagonal to the bottom of the square. This line represents the width of the diagonal plane of the cube. The square is developed from this diagonal plane by using the 45° VPs. 45 °-45 ° The 45 °-45 ° orientation is developed from the cube's diagonal plane that is also parallel to the picllire plane. (The geometry ifllerlocks with the 0°_90° axis.) 30°-60° Draw a 30" vertical line and draw lines to 30°-60° VPs. Rotate the vertical to a ground line. The line vanishing to the 30° VP is measured by the opposite 30° point. The line vanishing to the 60° point is measured by the opposite 15° point. (This is the measuring point construction often described in texts.) 30°-60° The 30°-60° oriefllation is a special case of the measuring poifll method because the measuring poiflls coincide with the 15 ° and 30° vanishing points. The Constructions Compared The four construc15 °-75 ° Depth of the 15 °_75 ° oriefllation is measured by the 15 ° VVT. (This construction is the tions are shown as 30" cubes within the 60° cone 0°_90° Alberti method, turned vertically.) The 30° and 60° vanishing points are used as checks of of visioll. The diagonals are used as checks of correct projectioll. correct projectioll. 10 Theatre Design & Technology / USITT / Fall 1984