Associating Sections with Tracks  

This procedure shows how to associate a trajectory involving a part with one or more sections.  You create the sections using the SectioningI_SectionP2.gif (335 bytes) command, which is available in the DMU Space Analysis workbench. 

For a detailed description of the section's positioning, see About Section Positioning, below.
Open the CHAINSAW.CATProduct file from the  online/cfysm_C2/samples/DMUApplications/explode online/cfysm_E2/samples/DMUApplications/explodedirectory. 

This path for this directory is provided relative to the documentation installation directory.

  1. In the DMU Space Analysis workbench, click SectioningI_SectionP2.gif (335 bytes).

  2. Adjust the sectioning plane per your needs, and create one or more sections in automatic update mode.

    See Sectioning for more information.

  3. Return to the DMU Fitting workbench.

  4. Click Shuttle .

  5. Create a shuttle with the sword and the chain.

  6. Click Track .

    The Track dialog box appears, along with the Player, Recorder, and the Manipulation toolbars. Associate Section is not available when the dialog box first appears.

  7. Select the shuttle under the Applications node on the specification tree.

    Associate Section becomes available.

  8. Click Associate Section .

    The Assign Section(s) dialog box appears.

  9. In the Available Sections list, select as many sections as you wish to use, and click the top, right-pointing arrow to transfer the sections to the Assigned Sections list.

  10. Click OK in the Assign Section(s) dialog box.

    For the section plane to be updated during simulation and while defining the track, the section plane needs to be in automatic update mode. After assigning a section in the Associate Section dialog box, any sections that are not in automatic update mode cause the Update Mode dialog box to appear.
    • If you click Yes, the sections have their update modes changed to automatic update mode. 
    • If you click No, the update modes for the sections are not changed, and the simulation data not reflect the defined track for the associated sections.
    For more information, see About Section Updating, below

  11. Click Yes.

    The sections are now associated with the trajectory. You can see them when you use the Player.

  12. Move the shuttle, and click Record .

    You can see the sections associated with track move with the shuttle when you use the Player.

  13. Click OK in the Track dialog box.
To disassociate a section, right-click on the track, and select track object > Definition.  Click the Associate Section button.  The Assign Sections dialog box appears.  From Assigned Section list, select the section you wish to disassociate from the track, then use the Unassign arrow to move the section to the Available Section list.
 

About Section Positioning

  During simulation, an assigned section is positioned by using an offset and the current track position. The offset is determined by the position of the section when it is assigned in relation to the current track position. This offset is used when positioning/moving a section along the defined trajectory of motion. 
  Since the offset is based on the current position of the track, the section is repositioned (per the offset) if the track is then set back to a different time. This subsequent position can differ from the initial position of where the section was added.
  During the creation of a move activity or track, the simulation of the move activity or track with an associated section is determined as follows:
  • For each step in the simulation, the initial offset is multiplied by the section's current position, and the section is positioned accordingly.
  • The section offset is maintained through the entire course of the simulation.
  • If the section plane is at a location other than the one within the simulation, then the section jumps to the simulation position when entering the simulation.
 

About Section Updates

  There are three modes to control how a section plane in updated:
  • Manual update (where the user controls when a section is updated)
  • Automatic update (where the section is always updated)
  • Freeze mode (where the section is not updated at all).

In order for the section plane to update during simulation (and the definition of the trajectory), the section plane needs to be in automatic update mode.