projection of points, lines and planes.pptx

Projections of lines and planes

1. Unit-1 Projection of Points,Lines&Plane 1

2. 2 NOTATIONS FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. IT’S FRONT VIEW a’ a’ b’ OBJECT POINT A LINE AB IT’S TOP VIEW a a b IT’S SIDE VIEW a” a” b”

3. 4 QUADRANT THEORY

4. 4 X Y 1st Quadrant 2nd Quadrant 3rdQuadrant 4th Quadrant F.V. 1 ST Quad. 2 nd Quad. 3 rd Quad. 4 th Quad. X Y Observer VP HP Observer THIS QUADRANT PATTERN, IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION) WILL EXACTLY APPEAR AS SHOWN ON RIGHT SIDE AND HENCE, IT IS FURTHER USED TO UNDERSTAND ILLUSTRATION PROPERLLY.

5. X Y 1st Quadrant 2nd Quadrant 3rdQuadrant 4th Quadrant F.V. Observer

6. Quadrants and Reference Planes

7. 7 PROJECTIONS OF A POINT IN THE 4 QUADRANTS HP VP POINT IN 2 nd QUADRANT VP HP P T P F HP VP POINT IN 3 rd QUADRANT HP VP POINT IN 4 th QUADRANT VP VP HP HP P T : TOP VIEW P F : FRONT VIEW P F P T P F HP VP POINT IN 1 st QUADRANT VP HP P T P F P T P P P P

8. 8 How you will draw on the sheet POINT IN 2 nd QUADRANT P T P F POINT IN 3 rd QUADRANT POINT IN 4 th QUADRANT P T : TOP VIEW P F : FRONT VIEW P F P T P F POINT IN 1 st QUADRANT P T P F P T y y y y x x x x

9. A a a’ X Y For Fv For Tv POINT A ABOVE HP & INFRONT OF VP X Y a a’ VP HP Fv above xy, Tv below xy. A a a’ X Y For Fv For Tv POINT A ABOVE HP & IN VP X Y a’ VP HP a Fv above xy, Tv on xy. A a a’ X Y For Tv For Fv POINT A IN HP & INFRONT OF VP X Y a VP HP a’ Fv on xy, Tv below xy.

10. Prob.1. Draw the projections of the following points on the same ground line, keeping the projectors 25 mm apart. A, in the H.P. and 20 mm behind the V.P. B, 40 mm above the H.P. and 25 mm in front of the V.P C, in the V.P. and 40 mm above the H.P. D, 25 mm below the H.P. and 25 mm behind the V.P. E, 15 mm above the H.P. and 50 mm behind the V.P. F, 40 mm below the H.P. and 25 mm in front of the V.P. G, in both the H.P. and the V.P.

11. Prob.3. The two points A and B are in the H.P. The point A is 30 mm in front of the V.P., while B is behind the V.P. The distance between their projectors is 75 mm and the line joining their top views makes an angle of 45 with xy . Find the distance of the point B from the V.P.

12. Prob.4. A point P is 20 mm below H.P. and lies in the third quadrant. Its shortest distance from xy is 40 mm. Draw its projections.

13. Prob.6. A point 30 mm above xy line is the plan-view of two points P and Q. The elevation of P is 45 mm above the H.P. while that of the point Q is 35 mm below the H.P. Draw the projections of the points and state their position with reference to the principal planes and the quadrant in which they lie.