COORDINATE SYSTEM

The functions in this menu are used to create and modify local coordinate systems. The functions are shown in Figure 9.13.1.

Toggles all created coordinate systems ON/OFF.

A detailed description of these functions is given in the following sections.

CREATE COORDINATE SYSTEM

This function is used to create a coordinate system.

Enter coordinate system ID and select OK in the next dialog window. The LCS dialog window appears, see Figure 9.13.2

As mentioned in previous chapters, this window is displayed when a current local coordinate system is needed. In those cases, the user can create a new LCS or select a system as the current LCS by selecting GLOBAL, LCS, or LAST.

GLOBAL

Defines the global coordinate system as the current local C. S.

LCS

Creates a local coordinate system as the current local C. S.

LAST

Defines the last coordinate system as the current local C. S.

There are two ways to create a LCS based on whether the DEFINED BY 3 LOCATIONS toggle is checked.

1. CHECKED

The user can select one, two or three points/nodes to create a system. To select a node, choose NEAR NODE. To select points, choose NEAR POINT.

Select a point and choose OK. The created LCS has an origin at the selected point and is a translation to the origin of the global system.

Select two points and choose OK. The first point is the origin. The U-axis is the vector from the first point to the second point. The LCS is a translation and a rotation from X to U of the global system.

Select three points. The P1 is the origin. The vector P1 P2 is the U-axis. The cross product of U and the vector P2 P3 is the W-axis and the V-axis is determined by the cross product WXU.

2. UNCHECKED

DEFINE ORIGIN, U-AXIS, V-AXIS, and W-AXIS will be active. To create a system in this case, the user needs to define the origin and an axis. The LCS system will be a translation and a rotation of the global system.

 DELETE COORDINATE SYSTEM

This function enables the user to delete a local coordinate system from the database.

-- Pick a coordinate system.

  -- Drag a window to include the coordinate system.

 --Define a multi-point region to include the coordinate system.

C.S. ID

Enter the starting and ending coordinate system ID and the increment in the next dialog window.

REJECT

Reject last selection.

Note: To remove the local systems/definitions from individual nodes, the user must reassign the nodes to the global coordinate system.

COPY COORDINATE SYSTEM

This function copies a selected coordinate system to a new location.

1. Pick the desired coordinate system displayed on screen using the default mouse pick or select GLOBAL C.S. to select the global coordinate system.

2. Define the new location using the INPUT COORDINATE dialog window. The selected coordinate system will be copied automatically.

MODIFY COORDINATE SYSTEM

This function is used to modify the definition of an existing coordinate system.

If MOVE is selected, the INPUT COORDINATE dialog window appears. The selected coordinate system will be moved automatically after a new location is defined.

If ROTATE is selected, the user must enter a rotation angle in the next dialog window. The coordinate system will be rotated automatically.

CURRENT COORDINATE SYSTEM

This function allows the user to designate a CURRENT status to a selected coordinate system.

IDENTIFY COORDINATE SYSTEM

This function is used to identify the type and origin of a coordinate system.

C.S. #### [SYSTEM TYPE] ORIGIN (x y z)

Where:

#### is the coordinate system numbers.

SYSTEM TYPE is the system type (rect.,

sphere, cylin.) and ORIGIN is the global

location of the system origin.