Orthographic Projection

Perpendicular

Ortho is a Greek word meaning _.

Orthographic Projection

To look straight at an object hides a dimension.

Orthographic Projection

Show the views of a 3D object projected in 2D.

Orthographic Projection

Collection of 2D drawings that work together to give an accurate overall representation of an object.

Front View

Pick a _ that is most descriptive of object.

Longest dimension

Normally the _ is chosen as the width (or depth)

Front, Top, and Side View

Most common combination of views is to use:

Glass Box Approach

• Place the object in a glass box.

• Freeze the view from each direction (each of the six sides of the box) and unfold the box.

First Angle Projection

The object is imagined to be in first quadrant.

First Angle Projection

The object lies between the observer and plane of projection.

First Angle Projection

The plane of projection is assumed to be non transparent.

Third Angle Projection

The object is imagined to be in third quadrant.

First Angle Projection

The plane of projection lies between the observer and object.

First Angle Projection

The plane of projection is assumed to be transparent.