Coordinate Systems

The position of every drawing point is defined by its coordinates. In the command prompt for a point position you can specify it on the screen or type the coordinates in the command line.

Specifying Coordinates

Coordinates can be specified in the Cartesian coordinate system and Polar coordinate system.

Cartesian and Polar coordinates can be relative and absolute.

Cartesian Coordinates

Cartesian coordinate system is defined by three perpendicular axes: X, Y and Z.

The origin of the coordinate system is the point of intersection of the three axes and has the coordinates: (0,0,0).

If you work in the plane, the Z coordinate is always 0, you have to specify X and Y. The X value is specified horizontally and Y value vertically. Positive coordinates are set to the right and above the origin, and negative to the left and below.

When working in three dimensions, you have to set the Z coordinates. By default, the Z axis is set perpendicular to the XY plane from the viewpoint of the observer. The positive coordinates are set above the plane and negative below.

For example, the coordinates (30,20) specify the point set 30 units in on the X axis and 20 units in on the Y axis.

Absolute coordinates are specified from the origin of the coordinate system. Absolute are used if the precise X and Y coordinates are known values.

Example:

The point with coordinates X=10 and Y=20 is the start and the point with coordinates X=30, Y=40 is the end of the line. To create the line, enter in the command line:

Relative coordinates are used when the distance from the previous point is a known value.

To specify relative coordinates, enter the @ symbol before their values. Values specified after the @ symbol are distances along the X and Y axes from the previous point.

To create a line from the previous example using the relative coordinates enter in the command line:

Polar Coordinates

In the Polar coordinate system, the absolute coordinates of a point are set by the distance from the origin and an angle between the polar axis and a line lying through the point and origin. The angle is set in degrees counter clockwise.

For example, the coordinates 40<30 specify a point on the plane, setting the distance as 40 units from the origin and with a 30 degrees angle from the X axis.

Example: The start point of the line is set as 20 units from the origin and at a 45 degree angle from the X axis; the end point is set as 50 units from the origin and 30 degrees from the X axis. Enter in the command line:

In the relative polar coordinates the distance to the point is set not from the origin, but from the previous point. The angle is specified from the polar axis to the line connecting the previous point and the defining point.

The @ symbol is used to specify relative coordinates.

Example:

The start point of a line is set as 20 units from the origin and at a 45 degree angle from the X axis; the end point is set as 40 units from the previous point and 30 degrees from the polar axis. Enter in the command line:

Specifying Points With “Direction – Distance”

The direct distance is set instead of entering coordinates; it is very useful for quickly entering the lengths of lines.

Using direct distance specifying, move the cursor in the desired direction and enter the length value in the command line at the command prompt: Specify next point:. If ortho mode is switched on, it is very useful for drawing perpendicular lines.

This method can be used in all commands, except commands where just a value is needed, for example Array, Divide etc.

Coordinate Filters

Coordinate filters are entered in response to a point request and define the axes along which coordinates will be set. You can enter the following filters: .x, .y, .z, .xy, .xz or .yz.

Coordinate filters allow you to input the coordinates of a point for each axis separately, specifying coordinates first along one axis, then along another.

Coordinate filters are useful when the value along one axis is determined by one characteristic point of the object, and along the other axis by another point. When using coordinate filters, it is possible to extract one coordinate value at a time from selected characteristic point of an object by using a snap.

For example, you need to enter the coordinates of a point, located in the center of a drawn rectangular window.

In response to a point request:

Specify point:

1. Enter filter: .x

The request will change its appearance. Now not all coordinates are requested, but only the value along the X axis:

Specify point: >> X

2. With the Midpoint snap activated, specify the horizontal edge of the window. This will define the coordinate of the point along the X axis.

Now the coordinates for the remaining Y and Z axes are requested:

Specify point: >> YZ

3. We are satisfied with the mode of cleaving coordinates from a point simultaneously along two specified axes. Therefore, it is not necessary to enter any other coordinate filters. With the Midpoint snap activated, select the vertical edge of the window. This will define the coordinates of the point along the Z and Y axes.

User Coordinate System

nanoCAD uses two kind of coordinate systems: world coordinate system and user coordinate system.

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Only one coordinate system is active at any time; it is called current.

World coordinate system is a base coordinate system and cannot be redefined (X axis is set horizontally, Y axis vertically and Z is perpendicular to XY plane). The main difference of the world coordinate system from the user coordinate system is its rigidity and that it can be the only one (for every model space and layout).

The usage of the user coordinate system has almost no restrictions; it can be placed at any point of the space and with any angle to the world coordinate system. UCS can be moved and rotated to specify points on the three dimensional and rotated views. Node points and base directions, defined by the SNAP, GRID and ORTHO modes are rotated with UCS.

Changing UCS Position

Commands for changing the UCS position set a new coordinate system, the so-called current coordinate system.

The current coordinate system inherits the parameters of the previous coordinate system, only the required values are changed.

World Coordinate System

The command sets the parameters of the world coordinate system for the current user coordinate system.

To set a World coordinate system quickly:

• 1. Click in the UCS name field on the Properties panel.
• 2. Open the drop-down list and select World:

Changing the UCS Position from the Command Line

Ribbon: View – Coordinates > New UCS

Toolbar: UCS –

Hot keys: ALT+U

Command line: UCS

Command options:

Face Sets the UCS in the plane of the face of a 3D object (submesh, polyface mesh, polygonal mesh, 3D-solid, parameteric solid).

Hover over the desired face to see how the UCS will be aligned. The Dynamic UCS (F6) mode must be active. The face is highlighted, and an icon is displayed near the cursor, previewing the direction of the UCS axes.

The origin point will be placed at the center of the cursor in the plane of the selected face.

The direction of axes of the new UCS depends on the edge that the cursor crossed when hovering over the face. So the X axis is set parallel to the intersected edge in the direction from the initial vertex of the intersected edge. The Y axis is

perpendicular to the X axis and directed towards the inside of the face. The Z axis is so that a right-handed coordinate system is obtained. When you hover the cursor over the same face from the side of another edge, the orientation of the UCS axes also changes.

Named Saves and restores frequently used UCS orientations by name.

The option starts the following prompt in the command line:

Enter an option [Restore/Save/Delete/?]

Options: Restore - Replaces the current UCS with a new from the list of named UCS. Save - Saves the current UCS with the specified name. Delete - Deletes

UCS from the list of named UCS. ? - Shows a list of named UCS.

Restore Replaces the current UCS with one from the list of named UCSs.

Save Saves the current UCS with a specified name.

Delete Deletes the UCS from the list of named UCS.

When deleting and restoring, named UCS can be selected in the command line:

Enter UCS name to delete : or [?/UCS1/UCS2/UCS]:

? Shows the list of named UCS.

Object Sets the origin and the direction of the UCS axes according to the geometry of the

existing object.

View Specifies a new coordinate system within the XY plane, set perpendicular to the

direction of sight and parallel to the viewport’s plane. The position of the origin is

not changed. The X axis is set horizontally and the Y axis is set vertically.

World Matches the current UCS to the World coordinate system (restores the World

coordinate system).

X/Y/Z Rotates the current UCS around the selected axis.

ZAxis Specifies the UCS using the positive direction of the Z axis: the origin is placed at

the first specified point; the positive direction of the Z axis is set through the

second specified point.

Command prompts:

Specify origin of UCS or

[Named/Object/View/World/X/Y/Z/ZAxis]

: Select start point of UCS.

Specify point on X-axis or : Specify a point on the positive ray of the X axis.

Specify point on XY plane or Specify a point on the positive ray of the Y axis in

: the XY plane.

Aligning UCS to an Object

Ribbon: View – Coordinates > Object

Menu: Tools – Coordinate system > Object

Toolbar: UCS –

Command line: SETUCSBYOBJECT

The command specifies the new position of the coordinate system origin for the current UCS; the direction of the axes is specified according to the geometry of the current object. The extrusion direction of the selected object specifies the positive direction of the Z axis for the new UCS.

Rules to create UCS, aligned to an object:

Command prompt:

Select object to align UCS: Select an object.

Setting UCS by View

Ribbon: View – Coordinates > View

Menu: Tools – Coordinate system > UCS View

Toolbar: UCS –

Command line: UCSVIEW

The command sets up a new UCS with XY plane parallel to the screen (view), while maintaining the coordinate origin.

New Origin for UCS

Ribbon: View – Coordinates > Set UCS by Point

Menu: Tools – Coordinate system > Point

Toolbar: UCS –

Command line: SETUCSBYPOINT

The command sets a new origin for the current UCS at the specified point.

Command prompt:

Specify Origin of UCS : Enter the coordinates of UCS origin or specify its position on the screen.

New Origin and Rotation Angle for UCS

Ribbon: View – Coordinates > Set UCS by point and angle

Menu: Tools – Coordinate system > Point and angle

Toolbar: UCS –

Command line: SETUCSBYPOINTANGLE

The command sets a new origin for the current UCS and the rotation angle of its axes.

Command prompt:

Specify origin of UCS [] : Enter the coordinates for the UCS origin or specify its position on the screen.

Specify point on X axis or :

Set the rotation angle on the screen by specifying a point, the positive direction of X axis will pass through, or enter its value in the command line. For example, as follows: 100<30.

Changing Direction of Z-Axis in UCS

Ribbon: View – Coordinates > UCS by Zaxis

Menu: Tools – Coordinate System > UCS by Zaxis

Toolbar: UCS –

Command line: UCSZAXIS

Setting UCS by the positive direction of Z axis: the coordinate origin of UCS moves to the first specified point, the positive direction of Z axis passes through the second specified point

Command prompts:

Specify new origin point or [Object] <0,0,0>

Specify point positive of Z-axis :

Enter the coordinates of UCS origin or indicate its position by cursor.

Specify point positive of Z-axis.

Defining a New UCS by 3 Points

Ribbon: View – Coordinates > UCS by 3 Point

Menu: Tools – Coordinate System > UCS by 3Points

Toolbar: UCS –

Command line: UCS3POINTS

Determining the orientation of a new user coordinate system by three points.

Command prompts:

Specify new origin point <0,0,0>: Enter the coordinates of UCS origin or

indicate its position by cursor.

Specify point on X-axis or : Specify point on positive X-axis.

Specify point on XY plane or : Specify point on positive XY plane.

Rotating UCS Around X, Y or Z Axes

Ribbon: View – Coordinates >

Menu: Tools – Coordinate System > UCS by X, UCS by Y, UCS by Z

Toolbar: UCS –

Command line: UCSX, UCSY, UCSZ

Rotating the current user coordinate system around the specified axis.

Rotate UCS around X axis

Rotate UCS around Y axis

Rotate UCS around Z axis

To rotate the current UCS around the specified axis:

• 1. Select the command to rotate around the desired axis.
• 2. Specify the rotation angle in the command line or on the screen.

Dynamic UCS

Status bar: Dynamic UCS

Hotkeys: F6

Command line: UCSDETECTCMD

When you create an object and move the cursor over a flat segment, the UCS temporarily aligns with it. This makes it possible to immediately draw in the plane of the highlighted face without additional execution of change-UCS commands. This feature is available in the Dynamic UCS mode.

In the dynamic UCS mode, UCS changes its orientation when you move cursor over a face of a 3D solid or a flat segment of a point cloud.

The dynamic UCS works on point clouds with surfaces, previously recognized by the Search Planes in Point Clouds command.

To align the grid plane with the XY plane of the dynamic UCS, check the Follow Dynamic UCS box on the Snap and Grid tab of the Drafting Settings dialog box or use the GRIDDISPLAY variable.

The direction of the UCS axes depends on the edge that the cursor crossed when moving to the face.

So, the X axis is set parallel to the crossed edge in the direction from the initial vertex of the crossed edge. The Y axis perpendicular to the X axis and is directed toward the inner part of the face. Z axis is set so that the right coordinate system is obtained.

When you move cursor toward the same face through another edge, the orientation of the UCS axes also changes.

At the first mouse click, the UCS is fixed and the first vertex of the created object is set. Then you can continue to draw in the selected plane. Upon exiting the object creation command, the UCS is reset to its original orientation.

To change the UCS again when specifying another vertex while the construction command is running, you need to hold down the CTRL+~ key combination.

You can change the UCS when specifying each vertex without using keyboard shortcuts. To do this, assign the value 1 to the UCSDETECTMODE variable (default = 0).

Upon exiting the command to create a vector object, the UCS is reset to its original position.

UCS Icon

Menu: View – Display > UCS icon

Command line: UCSICON

Manages the visibility and position of the UCS icon.

There are On, Off and Origin commands available in the View – Display > UCS icon.

To manage the visibility of the UCS icon use the Properties panel:

The full list of options available to manage the UCS icon is available in the command line.

Command options:

ON Shows the UCS icon.

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OFF Hides the UCS icon.

All Parameters of visibility for all viewports. If this option is not used, the

parameters of the UCS icon are specified only for the current viewport.

The option starts the following prompt in the command line:

Entry an option or [ON/OFF/Noorigin/Origin/] :

If the option is not used, parameters of UCS icon are set only for the current

viewport.

Noorigin Shows the UCS icon in the left corner of the screen regardless of UCS origin.

Origin Shows the UCS icon at the origin (0,0,0) of the current UCS. If the origin of the

UCS is outside the visible part of a drawing, the icon is shown in the left corner

of the screen.

Command prompt:

Entry an option or [On/Off/All/Noorigin/Origin] <“On”>: Select the required option.

Named UCS

Ribbon: View – Coordinates > Named UCS…

Menu: Tools – Named UCS…

Toolbar: UCS –

Command line: UCSMAN, UC

The command opens the UCS dialog box, where you can select from the specified UCS, the parameters and UCS icon modes for viewports.

The UCS dialog box can be opened from the Properties panel:

Named UCS Tab

This tab contains the list of coordinate systems specified in the current drawing.

If the UCS is not saved or named, it is shown as Unnamed in the list.

The current UCS is marked with sign.

To set a UCS as current:

• 1. Select the UCS from the list.
• 2. Select the Set Current button.

You can set the UCS as current by double clicking on the UCS name or select Set Current from the context menu:

The sign of the set coordinate system is displayed in the graphic area of the drawing, which allows you to control the choice with a variety of named UCSs.

The Details button (or command from the context menu) opens the UCS Details dialog box with information about the coordinates of the selected UCS:

To delete a UCS:

• 1. Select the UCS from the list,
• 2. Open the context menu,
• 3. Select Delete.

To rename a UCS:

• 1. Select the UCS from the list,
• 2. Open the context menu,
• 3. Select Rename,
• 4. Enter the new name.

To implement changes

1. Click the ОК button in the UCS dialog.

Orthographic UCS Tab

This tab contains six orthogonal coordinate systems which can be set for a UCS selected in the Relative to drop-down list. All named UCS existing in the current drawing are shown in the Relative to dropdown list.

To set an orthogonal UCS:

• 1. Select the UCS from the list,
• 2. Select the Set Current button.

You can set an orthogonal UCS by double clicking on the UCS name or select Set Current from the context menu:

Options of the context menu:

Set Current Sets the orthogonal UCS as current one.

Reset Restores the origin of the selected orthogonal coordinate system (the origin has (0,0,0)

coordinates of the base coordinate system).

Depth Sets the direction between the XY plane of the orthogonal UCS and the parallel plane,

set through the origin of the base coordinate system.

The parallel plane can coincide with XY, YZ or XZ planes of the base coordinate system.

Details Opens the UCS Details dialog box with information about the coordinates of the

selected orthogonal UCS.

To set an orthogonal UCS:

1. Click in the UCS name field on the Properties panel.

2. Open the drop-down list and select appropriate orthogonal UCS:

Settings Tab

The tab is used to show and change the UCS icon modes and the UCS modes saved with the viewport:

Parameters:

UCS icon setting

On Displays the UCS icon in the current viewport.

Display at UCS origin point

Displays the UCS icon in the current viewport at the origin. If the UCS origin is outside the viewport and the parameter is switched off, the UCS icon is

specified in the left corner of the viewport.

Apply for all active viewports Applies the UCS icon modes to all the active viewports of the current

drawing.

UCS settings

Save UCS with viewport

Saves the UCS mode with the viewport. If the parameter is switched off, the UCS of the current viewport is used for the specified viewport.

Update view to Plan when Restores the view in plan when the coordinate system is changed in the current viewport.

UCS is changed

UCS for Viewports

Different model views can be shown for different viewports. For example, a configuration of three viewports can have the top view in one viewport, the front view in another and the right side view in the third viewport. You can set and save the UCS for every viewport.

If the Yes parameter is set in the UCS per viewport field on the Properties panel, the UCS of the viewport is saved before switching to another viewport. When you switch back to the viewport, the saved UCS restores.

If the No parameter is set, the UCS of the viewport always coincides with the UCS of the current active viewport.

Manage saving of the UCS for every viewport on the Properties panel: