Lecture Notes on 2D Projections of 3D Objects

Introduction

• 2D Projections of 3D Objects: Involves visualizing how a three-dimensional object appears from different views or perspectives.

Types of 2D Projections

1. Front Elevation

   • Represents the object as viewed from the front.
   • Shows only the faces directly facing the viewer.

2. Side Elevation

   • Represents the object as seen from the side.
   • Displays the faces visible from a side perspective.

3. Plan View

   • A top-down, bird’s eye view of the object.
   • Shows the faces that are facing directly upwards.

Example Analysis

• Task: Draw front elevation, side elevation, and plan view for given shapes.

• Front View:

  • Labelled in the problem to indicate which side is considered the front.
  • Example: View from the front shows five squares projected onto a 2D plane.

• Side View:

  • Example: Shows nine squares forming a 3x3 block.

• Plan View:

  • Example: Also shows nine squares, similar to the side view in this case.

Common Shapes' Projections

1. Square-based Pyramid

   • Front and Side Elevations: Both appear as triangles.
   • Plan View: Appears as a square with two diagonal lines representing the triangle’s edges.

2. Cylinder

   • Front and Side Elevations: Appear as rectangles.
   • Plan View: Appears as a circle.

Conclusion

• Practice these concepts using the platform link provided for further understanding.
• Questions and engagement in comments are encouraged.