autocad computer

1. 3D Drawing
Perspective Drawing and Ellipsis

2. 3D DRAWING
A 3 dimensional shape, object or thing you draw
upon a piece of paper that shows you the perspective
and shading used to help make the drawing more
realistic.

3. Perspective Drawing
Perspective drawing is used in many different fields. Engineers or
industrial design engineers will draw using an isometric grid to give
a fixed perspective. They may draw the different parts or draw an
entire building.

4. ONE-POINT perspective drawing. This
type of perspective drawing is based on
one focal point or vanishing point. In
these types of drawing one will notice
that most all lines will meet at exactly
one point. This is the point of infinity.
TWO POINT perspective is just what it
sounds like. Instead of only one point of
infinity there are two. Take a look at this
castle wall.

5. THREE-POINT perspective is a bit more involved. The constructions are the
same as one and two point but with three vanishing points. With three
points it can get a little confusing. Take a look at this GSP file of two boxes
with three-point perspective.

6. Ellipsis
An ellipse is simply a circle seen in perspective. This is an important concept to keep
in mind.
An ellipse, therefore, must conform to the same rules as a circle - it consists of arcs,
it contains no straight lines and, if divided into quarters, each segment is identical
to the other three.