Coordinate Control in ZWCAD Flex | Guide for UCS, Dynamic Input & 3D Coordinates

Accurate drawing begins with precise control over coordinates. ZWCAD Flex offers multiple tools to help users define, enter, and manage coordinates effectively in both 2D and 3D environments. This guide introduces key features for coordinate control, including User Coordinate System (UCS), Coordinate Entry methods, Dynamic UCS, Dynamic Input, and UCS management tools.

 

Understanding the User Coordinate System (UCS)

The User Coordinate System, or UCS, lets you set your own coordinate origin and axis directions. Compared to the fixed World Coordinate System (WCS), the UCS is more flexible and is especially useful when you're working on complex drawings.

 

The UCS provides a work plane (the XY plane) where you can draw and edit objects. It also defines:

 

· Where coordinates start (the origin)

· Which way the X, Y, and Z axes point

· How angles are measured

· The direction of horizontal and vertical features like Ortho Mode, Polar Tracking, and Object Snap Tracking

 

The UCS also affects how the grid, hatch patterns, text, and dimensions are aligned. In 3D drawings, it controls the orientation of work planes, projection planes, and the Z axis.

 

When you first start a drawing, the UCS and WCS are the same. Unlike the WCS, which is fixed, the UCS can be moved or rotated to suit your needs. However, in layout view, the UCS only supports 2D operations.

 

By default, the UCS icon appears in the bottom-left corner of the model space or layout viewport. In Model Space, it looks like coordinate axes with arrows. In Layout Viewports, it appears as a right triangle.

 

 

The UCSICON command allows you to control the display status of UCS icon through command line options.

 

· Control whether to display or hide the UCS icon.

· Control the properties of UCS icons, including icon style, icon size, and icon color.

· Control whether the UCS icon is fixed at the coordinate origin.

 

Entering Coordinates in ZWCAD Flex

When you're prompted to specify a point in the command line, you can either click a location in the drawing area or type the coordinates directly. ZWCAD Flex supports various ways to enter coordinates, including 2D and 3D, and using absolute or relative formats.

 

Coordinate Types

2D Coordinates

You can use:

· Cartesian (X, Y): Based on distance along X and Y axes.

· Polar (Distance < Angle): Based on distance and direction.

 

3D Coordinates

You can use:

· Cartesian (X, Y, Z)

· Cylindrical (Distance < Angle, Z)

· Spherical (Distance < Angle1 < Angle2)

 

All coordinate types support:

· Absolute coordinates (measured from the origin)

· Relative coordinates (measured from the last point)

 

Cartesian Coordinates

Cartesian coordinates specify how far a point is from the origin along the X, Y, and Z axes.

 

2D Cartesian (X, Y)

· Format: X,Y

· Example:

Command: LINE

Specify the first point: #-1,1

Specify the next point or [Angle/Length/Undo]: #3,5

 

Here, # means absolute coordinates. A line is drawn from (-1,1) to (3,5).

 

 

Relative 2D Cartesian (@X,Y)

· Format: @X,Y

· Example:

Command: LINE

Specify the first point: #-2,1

Specify the next point or [Angle/Length/Undo]: @3,4

Specify the next point or [Angle/Length/Undo]: @-3,2

 

This draws two connected lines. The @ symbol tells ZWCAD to calculate the next point based on the last one.

 

 

3D Cartesian (X,Y,Z)

· Format: X,Y,Z or @X,Y,Z

· Example:

Command: LINE

Specify the first point: 3,4,5

Specify the next point or [Angle/Length/Undo]: 6,8

 

If Z value is not given, it defaults to 0. Once specified, the Z value stays until changed.

 

Polar Coordinates

Polar coordinates define a point using distance and angle.

 

Absolute Polar Coordinates

· Format: #Distance

· Example:

Command: LINE

Specify the first point: #3<30

Specify the next point or [Angle/Length/Undo]: #8<-60

 

3<30 means 3 units from origin at 30° counterclockwise from X axis. 8<-60 means 8 units at 60° clockwise.

 

 

If you want to force absolute polar based on WCS, add an asterisk (*) prefix when entering polar coordinates, namely entering coordinates in the *distance

 

Relative Polar Coordinates

· Format: @Distance

 

The figure below displays two line segments drawn with relative polar coordinates. The first line segment starts at #3<30, which indicates a distance of 3 units from the coordinate at an angle of 30 degrees. The second point specified uses the relative coordinates @8<45, which means a distance of 8 units from the first point at an angle of 45 degrees. The second line segment starts at the endpoint of the first line and ends at a point with relative polar coordinates of @5<160, which indicates a distance of 5 units from the last point at an angle of 160 degrees.

 

 

3D Cylindrical Coordinates

Cylindrical coordinates specify a point using:

· Distance from origin in XY plane

· Angle from X axis

· Z height

· Format: Distance

 

In the figure below, input 9<30,10 in the command line to define a point 9 units from the UCS origin in the XY plane, 30 degrees from the X axis in the XY plane, and 10 units along the positive Z axis.

 

 

Like the entry of other coordinates, you can use absolute coordinates relative to the coordinate origin and relative coordinates relative to the last point for 3D cylindrical coordinate entry.

 

3D Spherical Coordinates

3D spherical coordinates define the location of a point by using the distance of the point from the XY plane, the angle from the XY plane, and the angle from the X axis in the XY plane.

 

The entry format of spherical coordinates is: r<(angle from X axis in XY plane)<(angle from XY plane)

 

 

Like the entry of other coordinates, you can use absolute coordinates relative to the coordinate origin and relative coordinates relative to the last point for 3D spherical coordinate entry.

 

Dynamic UCS

Dynamic UCS temporarily aligns the XY plane of the User Coordinate System (UCS) to the 3D surface your cursor is hovering over. As you move the cursor across different surfaces, the UCS updates automatically to match the surface under the pointer.

 

This feature is especially useful when you're working with 3D solids, because it helps you draw precisely on different faces without manually changing the UCS each time.

 

Dynamic UCS supports the following surface types:

· Flat surfaces of 3D solids

· Planar meshes

· Planar point cloud segments

· Other planar geometry

 

How to Enable Dynamic UCS

Click the Dynamic UCS button in status bar at the bottom of ZWCAD to turn this feature on or off.

 

In the figure below, you want to draw a half arc on the side of a box.

 

1.Run the ARC command.

2.Move your cursor to the side of the box.

3.The UCS icon automatically aligns to the selected plane.

4.Now specify the arc’s center, start point, and end point directly on that face.

 

 

As shown in the example, Dynamic UCS helps you "lock onto" the correct working plane without extra steps. This is especially helpful when you’re snapping to shared edges or corners of multiple surfaces, making your 3D drafting faster and more accurate.

 

Dynamic Input

Dynamic Input displays a tooltip box near your cursor, allowing you to type values or options directly in the drawing area - without having to move your eyes to the command line. This improves drawing efficiency by keeping your focus where you're working.

 

To turn Dynamic Input on or off, click the Dynamic Input button in the status bar, or press F12.

 

You can further customize its display properties in the Drafting Settings dialog box by running the DSETTINGS command.

 

Dynamic Input includes three parts:

· Pointer Input

· Dimension Input

· Dynamic Prompts

 

Pointer Input

When Pointer Input is enabled, the current coordinate values appear next to the cursor when you're prompted to specify a point. You can type values directly at the cursor.

 

 

By default, absolute Cartesian coordinate is displayed when specifying the first point, and relative polar coordinates are displayed when specifying the second and subsequent points (relative Cartesian coordinates when executing the RECTANG command).

 

 

· If you enter "#" at pointer position, you can switch to absolute polar coordinates in dynamic input.

 

 

· If you enter "<" and angle value at pointer position, you can switch to polar tracking in dynamic input.

 

 

· If you enter "*" at pointer position, you can switch to world coordinate system in dynamic input.

 

 

Dimension Input

When Dimension Input is enabled, tooltips appear when you're editing objects (such as stretching with grips). These tooltips show distances, angles, or other values you can directly edit.

 

Editable values include final length or angle, angle change, angle change, length change, arc radius, and absolute angle.

 

 

You can press Tab to move between input fields. After entering a value, pressing Tab again can lock that field to fix the direction or distance of the point you're editing.

 

Dynamic Prompts

When Dynamic Prompts are enabled, command options (normally shown in the command line) appear near the cursor as you draw.

 

You can type your response directly in the tooltip, or still use the command line if you prefer, both methods work.

 

 

During the command execution process, pressing the up arrow can display previous input. If the command contains options, you can use the down arrow to expand option list, and then use the up and down keys to switch between options.

 

 

Manage User Coordinate System

Rotate UCS

You can use the UCS command to rotate the coordinate system around the X, Y, or Z axis. Rotating the UCS helps you align the coordinate axes with objects more easily. 

 

When the UCS is rotated, the snap, grid, and orthogonal drawing directions also rotate to match the new orientation.

 

In the figure below, the UCS is rotated 60° around the Z axis.

 

 

Move UCS

To move the UCS, you can use a combination of the UCS and UCSICON commands.

· Use the UCS command to set a new origin point.

· Then use UCSICON to display the UCS icon at the new origin.

 

This is useful when you want to shift the entire coordinate system to work on a different area of your drawing.

 

 

UCS Settings

Use the UCSMAN command to manage saved UCS settings through a dialog box.

 

You can:

· Set the target UCS as current.

· Rename a UCS.

· Set the depth of orthogonal view.

· Set UCS icons and updates.

 

Switch UCS

The PLAN command allows you to switch between the current UCS, UCS, and WCS. This is useful for restoring a standard top-down view or working in different orientations.

 

Assign UCS to Viewports

When working in multiple viewports, you can assign different User Coordinate Systems (UCS) to each one. This makes it easier to edit objects from different angles, such as top, front, or isometric views.

 

The behavior of the UCS icon in each viewport is controlled by the UCSVP system variable.

 

How UCSVP Works

· UCSVP = 0

The UCS icon shows the UCS of the currently active viewport. If you switch to a different viewport, the UCS icon updates to match that one.

 

· UCSVP = 1

The UCS icon is locked to the UCS of that specific viewport. Even if you switch to another viewport, the UCS icon in this one stays the same.

 

Imagine you have three viewports open in model space: top view, front view and southeast isometric view (currently active)

 

If UCSVP = 0 in the isometric viewport, the UCS icon shows the UCS of the current active viewport. When you activate another viewport, the icon in the isometric view also updates.

 

 

If UCSVP = 1 in the isometric viewport, the UCS icon always shows the isometric UCS, even when another viewport is active.

 

 

This setting helps maintain visual consistency when working in multiple view directions.