ENG 004 Lecture 6, Oct 16, 2012

Announcements

Topics

Use of Grids

Geometric Modeling

Coordinates

Geometric Modeling

Units of Measure

Coordinates

In practice, Cartesian coordinates are default in most CAD packages.

Also the right-handed orientation is used.

Cartesian Coordinate System

2D Coordinate Systems

Rectangular: (x, y)

Polar: (r, θ)

2D Coordinate Systems

3D Coordinate Systems

Rectangular: (x, y, z)

Cylindrical: (rc, θ, z)

Spherical: (rs, θ, φ)

Conventions

Right handed systems are the dominant convention.

Coordinate planes

3D Coordinate Systems

Grid Examples

Rectangular Grid

Isometric Grid

/

#