Engineering Graphics 2018-19-I Lecture 9 TA101A Engineering Graphics 2018-19-I By Dr. Mukesh Sharma Professor DEPARTMENT OF CIVIL ENGINEERING INDIAN INSTITUTE OF TECHNOLOGY KANPUR KANPUR-208016, INDIA

Parallel Downward receding direction

Isometric and Oblique projections

Front View Right Side View Visualize the Object Oblique view of an object with Oblique surfaces

Note: a’,a’’,b’,b’’,c’c’’ exist but not shown Due to space limitation e,e’e” 5,5’,5” 5 e 5’e’ 5”e’’ d,d’d” 4,4’,4” 4d 4’d’ 4”d” 3,3’,3” c 3 c 3’ c’ 3” c” 2,2’,2” b 2b 2’b’ 2”b” a 1,1’,1” 1 a 1’ a’ 1” a” 5” e” 4” Projection of front face in RSV, If front face not oblique but parallel to PP 5’ 3” 4’ 2” 1” e’ 3’ 5 4 e b’ 2’ a’ 3 1’ b 2 a 1

Oblique View of Cylinder

What kind of 3-d Pictures are these? As seen by eyes - Pleasing Perspective Pictures – How different are these from isometric/oblique drawing

Projection line Horizon line Axis of vision Ground Line Picture Plane Horizon line Axis of vision Horizon Plane SP Ground Plane Center of vision Ground Line

Front View Objective is to get this picture on PP Key is convergence of rays at SP Picture Plane (PP) (transparent) TOP VIEW Any Convenient Distance PP HL GL AV cv SP X Front View Horizon line (HL) Horizon Plane (HP) SP(EYE) Ground Plane Center of vision (CV) Ground Line (GL)

b C B b b A c d b a a a a For A, B and C examine Projection on PP g d h g d f b a a a h e f e a b ø a ø ø PP PP PP u PP a1 b1 LVP HL RVP HL VP RVP HL ø ø SP SP SP For A, B and C examine Projection on PP