Point filters provide a method of locating a point in a drawing relative to another point without specifying the entire coordinate. Using a point filter, you can enter partial coordinates, and then the program prompts you for the remaining coordinate information. To use xyz point filters, respond to the prompt for a coordinate with a filter in the following form:
.coordinate
where coordinate is one or more of the letters x, y, and z. The program then prompts you for the filtered coordinate(s). For example, if you type .xy, the program prompts you to select a point whose xy-coordinate you want, and then prompts you for the z-coordinate. The filters .x, .y, .z, .xy, .xz, and .yz are all valid filters.
You can use point filters when you work in two dimensions to locate points in relation to existing entities. For example, to draw a circle centered in a rectangle, start the Circle command, and then respond to the prompts as follows:
2Point ? 3Point ? RadTanTan ? Arc ? Multiple ? <Center of circle>: .y
Select Y of: mid
Snap to midpoint of: (select the left side of the rectangle)
Still need XZ of: mid
Snap to midpoint of: (select top of the rectangle)
Diameter ? <Radius>: (specify radius of circle)
You can use point filters to center the circle by separately selecting the midpoints of two sides of the rectangle (A and B) and then specifying its radius.
You can use point filters when you work in three-dimensional space to locate points in two dimensions and then specify the z-coordinate as the elevation above the xy plane. For example, to begin drawing a line from a point with a z-coordinate 3 units above the center of a circle, insert the circle, and then start the Line command and respond to the prompts as follows:
ENTER to use last point ? Follow ? <Start of line>: .xy
Select XY of: cen
Snap to centerpoint of: (select a point on the circle)
Still need Z of: 3 (locates the starting point 3 units above the center of the circle)
Length of line: (specify the length of the line)
You can use point filters to draw a line by first selecting a point in the xy plane (A), specifying the z-coordinate (B), and then specifying the length of the line (C).