Coordinate input

When you create entities in a drawing, they are located in relation to the underlying Cartesian coordinate system of the drawing. A drawing has a fixed coordinate system called the World Coordinate System (WCS).

You can also define arbitrary coordinate systems which are called User Coordinate Systems (UCS). They can be located anywhere in the WCS and oriented in any direction.

To specify points and distances using the keyboard, you can use the following formats:

  • Cartesian coordinates: x,y,z
  • Cylindrical coordinates: R<alpha,z
  • Spherical coordinates: R<alpha<beta

Relative coordinates

When you type the @-character in front of the entry, the coordinates are calculated with respect to the previous point. This technique is called  Relative Coordinates.

When Dynamic Dimensions are active and you type a value in the Length field and add a comma (,), the content of the Length field is copied to the Command line and the @-character is placed in front automatically, which allows you to specify the next point using relative coordinates with respect to the previous point.

Absolute coordinates

When a user-defined coordinate system is active, you can enter absolute coordinates (World coordinates) if you add an asterisk (*) in front. For example, *0,0 refers to the origin of the WCS (World Coordinate System).

Working with Cartesian coordinates

The Cartesian coordinate system uses three perpendicular axes: the x-axis, the y-axis and the z-axis. All axes originate in the origin point of the coordinate system. The x-axis and the y-axis define a horizontal plane, while the x-axis and the z-axis respectively, the y-axis and the z-axis define vertical planes. A point is defined by its distances to the yz-, xz- and xy- planes. These distances are called the xyz-coordinates of a point.
  • Type the x-, y- and z- coordinates separated by commas to enter the absolute Cartesian coordinates of a point.
  • When the z-coordinate is omitted, the point is placed in the xy-plane (Z = 0).
  • Type the @-character in front of the entry (@x,y) to specify the coordinates with respect to the previous point. This technique is called  Relative Cartesian coordinates.

Working with cylindrical coordinates

A cylindrical coordinate system uses three perpendicular axes: the x-axis, the y-axis and the z-axis. All axes originate in the origin point of the coordinate system. The x-axis and the y-axis define a horizontal plane, while the x-axis and the z-axis respectively, the y-axis and the z-axis define vertical planes.

A point is defined using the following format: R<alpha, z.

  • R = distance to the origin in the xy-plane.
  • <alpha = the angle between R and the x-axis (positive angles are measured counter clockwise)
  • z = the height above the xy-plane.
  • When the z-coordinate is omitted, cylindrical coordinates are referred to as polar coordinates.
  • Type the @-character in front of the entry to calculate the coordinates with respect to the previous point.

Working with spherical coordinates

The spherical coordinate system uses three perpendicular axes: the x-axis, the y-axis and the z-axis. All axes originate in the origin point of the coordinate system. The x-axis and the y-axis define a horizontal plane, while the x-axis and the z-axis respectively, the y-axis and the z-axis define vertical planes.

A point is defined using the following format: R<alpha<beta

  • R = distance from the origin
  • <alpha = angle in the xy-plane (positive angles are measured counter clockwise)
  • <beta = angle measured from the xy-plane (positive angles are measured counter clockwise, above the xy-plane)