Bottom of the Page

You can use coordinate filters to extract one coordinate value at a time from locations on existing objects.

Coordinate filters
specify a new coordinate location by using the *X* value from
one location, the *Y* value of a second location,
and, for 3D coordinates, the *Z* value of a
third location. When used with object snaps, coordinate filters
extract coordinate values from an existing object.

Coordinate filters are commonly used to locate
the center of a rectangle and to locate the projection of a 3D point
on the *XY* plane of the UCS.

To specify a filter at the Command prompt, enter
a period and one or more of the letters *X*, *Y*,
and *Z*. The next entry is limited to
a specific coordinate value.

Example: Use of Coordinate Filters in 2D

In the following illustration, the hole in the
holding plate was centered in the rectangle by extracting the *X,Y* coordinates
from the midpoints of the plate's horizontal and vertical line segments.

Here is the Command prompt sequence:

Command: *circle*

Specify center point
for circle or [3P/2P/Ttr (tangent tangent radius)]: .*x*

of: *mid*

of: *Select
the horizontal line on the lower edge of the holding plate*

of: (need YZ): *mid*

of: *Select
the vertical line on the left side of the holding plate*

of: Diameter/<Radius> *Specify
the radius of the hole*

Coordinate filters work only when the program prompts you for a point. If you try to use a coordinate filter at the Command prompt, you see an error message.

Example: Use of Coordinate Filters in 3D

This example shows how to use coordinate filters
to create a point object at the center (centroid) of a 3D object.
Hidden lines have been removed for clarity. The *X* value of the
new point is extracted from the first location specified, the *Y* value
from the second location, and the *Z* value from
the third. The three values are combined to form the coordinate
values of the new point.

Command: *point*

Point: *.x*

of mid

of select object (*1*)

(need YZ): *.y*

*of mid*

of select object (*2)*

(need Z): *mid*

of select object (*3)*