Form: Frame Local Axis, Frame Advanced Axis
The program automatically determines the local axis for frames from their connectivity and orientation. The Assign > Frame > Local Axis command can be used to modify these axes when necessary.
Select one or more frame objects to be assigned a modified local axes.
Click the Assign menu > Frame > Local Axes command to access the Frame Local Axis form.
Type a value in the Angle in Degrees edit box. This is an angle by which local axis 2 of the object will be rotated around the local axis 1. Local axis 1 is along the length of the object. By default local axis 2 is always in the 1-Z plane, except if the object is vertical and then it is parallel to the global X axis. The definition of the local axes follows the right-hand rule. The angle is measured counter-clockwise as positive if the local axis 1 is pointing towards you.
Note: By default global Z is taken as the 3D View Up Direction. If needed, change the UP direction for the display using the Options menu > 3D View Up Direction command. If the UP direction is changed, it will only affect the display of the model and does not affect the local axes definition in any way.
Check the Advanced Axes check box and click the Advanced button to display the Frame Advanced Axis form. Use the Frame Advanced Axis form to refine the specification of the local axes for the selected object(s).
Default option - When this option is selected, the other areas of the form are not available and no further input is required.
Advanced option - When this option is selected, the input required on the form changes depending on the option selected in the Plane Reference Vector Specified by area of the form.
Local Plane - Select the local plane for the frame from the drop-down list.
Plane Reference Vector Specified by - Choose one of the following options to specify how the plane reference vector will be specified:
Coordinate Direction - Use this option to specify that the plane reference vector be based on coordinate direction. When this option is selected, the form will display a Coordinate System drop-down list and a Plane Coordinate Direction area with Primary and Secondary Dir (Direction) drop-down lists. Select the coordinate system for the reference vector and then choose a coordinate direction from each drop-down list.
Two Joints - Use this option to specify that the plane reference vector be based on two specified joints. When this option is selected, the lower portion of the form will display a Two Joints for Plane Reference Vector area with Plane Joint 1 and Plane Joint 2 drop-down lists. The lists consist of the joints included in the model and a None selection. Choose the two joints to be used to specify the plane reference vector.
User Vector - Use this option to define the vector based on user-specified coordinate values. When this option is selected, the form will display a Coordinate System drop-down list and a User Plane Reference Vector area with edit boxes for Plane Vector X, Plane Vector Y, and Plane Vector Z. Select the coordinate system for the reference vector and then enter coordinate values in the edit boxes to specify the plane reference vector.
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