Drawing techniques

Question 1

describe orthographic projection

Answer 1

• show a 3d object from three angles: front view, plan view, side/end view
• dimensions always given in mm
• symbol in top-right corner - target with two rings and a trapezium (shorter length on left)
• process:
  -front view is drawn in bottom left corner
  -use dotted lines to create the outline of the side view and complete the shape in line with the front view
  -draw a line at 45 degrees in the top right corner of the front view
  -draw dotted lines going up from the end view, when they reach the 45 degree line begin the dotted lines to the left; this creates the outline for the plan view
  -mark the hidden details on

Question 2

describe two-point perspective

Answer 2

• two points are marked at either end of the horizon line
• uses lines that are vertical or to the vanishing point
• start with the front vertical edge then draw lines to the vanishing point
• provides a realistic drawing that gives an idea of width/height/depth

Question 3

describe one-point perspective

Answer 3

• uses lines that are vertical, horizontal, or to the vanishing point
• first the front view of the object is drawn, then draw lines to the vanishing point