Chapter 4
Using Tcl to Control the HyperMesh Session
The macros that have been created thus far are very powerful in their automation of repetitive tasks. However, there are limitations. For example, in the LoadCol macro which creates a load collector called forces, the name of the load collector is hard-coded. If the user wanted to create a load collector with a different name, it would require editing the name in the userpage.mac file.
The Tcl scripting language can be utilized to provide support for more advanced tasks. Using the previous example, Tcl could be used to request a name for the load collector from the user and use that information to tell the HyperMesh session to create a load collector with the user provided name.
HyperMesh Commands vs. Tcl Modify Commands
The HyperMesh commands that were presented in the previous chapter are also available through their Tcl Modify commands. For the HyperMesh Tcl Modify commands, the command syntax has changed and does not contain
parentheses and commas; they have been replaced with a blank space. Also the wrapper commands *beginmacro() and *endmacro() are not used. For example, let’s compare the following HyperMesh command macro and its Tcl equivalent.
Chapter 4: Using Tcl to Control the HyperMesh Session
Macro in userpage.mac file Tcl Script
*beginmacro("macroJpeg") Not used in Tcl
*setbackgroundcolor(255,255,255) *setbackgroundcolor 255 255 255
*setmeshlinecolor(6) *setmeshlinecolor 6
*jpegfile() *jpegfile
*setbackgroundcolor(0,0,0) *setbackgroundcolor 0 0 0
*setmeshlinecolor(0) *setmeshlinecolor 0
*endmacro() Not used in Tcl
Notice that while the parentheses and commas have been removed, each of the commands still begin with an asterisk (*) and that the command name hasn’t changed. In addition to the syntax change, Tcl core commands can also be used (these are the commands presented in Chapter 1). The addition of the Tcl
commands provides added functionality to the macros.
Tcl GUI Commands and Tcl Query Commands
In addition to the HyperMesh Tcl Modify Commands, there are HyperMesh Tcl GUI commands and HyperMesh Tcl Query Commands. As their names suggest, these commands either make changes/updates in the HyperMesh GUI or they query the HyperMesh database for information. Also, these commands have the prefix “hm_”. We will go over a few basic HyperMesh input widgets and a table of common commands will be presented.
Basic HyperMesh Input Widgets
One of the most basic things that need to be done in a macro is to enter data or text to be used in the HyperMesh macro. For example, imagine we are creating a load collector as we did in the previous chapter. In that example, the name of the load collector was hard-coded into the macro. Using the hm_getstring command, a string value is returned by providing the user with a HyperMesh panel. The syntax is:
hm_getstring ?caption? ?message?
where both the caption and message are optional arguments. The caption is shown in the panel while the message is shown in the message bar. For example:
hm_getstring “Load collector name” “Enter a name for the load collector”
produces the following panel and message in HyperMesh
Chapter 4: Using Tcl to Control the HyperMesh Session
Panel produced by hm_getstring
This command can be used with the set Tcl command to assign the string entered in the panel to a variable:
set loadname [hm_getstring “Load collector name” “Enter name for load collector”]
In addition to getting a string, the hm_getint and hm_getfloat commands can be used to get values by posting a panel in the HyperMesh panel area. The hm_getint command returns a user input integer value while hm_getfloat returns a user input floating point value. Both these commands have the same options as the hm_getstring command. As an example, let’s assign a floating point value to a variable called force:
set force [hm_getfloat “Force” “Enter force value”]
Panel produced by hm_getfloat
With the addition of the HyperMesh Tcl commands, there are a few commands which replace the HyperMesh Modify commands. Specifically there are the hm_createmark and hm_clearmark commands. These commands perform the same functionality as the *createmark and *clearmark commands, but they are the HyperMesh Tcl equivalent. The advantage of using these
commands is that it avoids situations where additional Tcl commands need to be used to evaluate the HyperMesh command. Using hm_createmark and
hm_clearmark when writing Tcl scripts is the more efficient and recommended method.
Chapter 4: Using Tcl to Control the HyperMesh Session
The following table contains a list of the commonly used HyperMesh Tcl
commands as well as a short description of that command. For a full explanation of the commands, please refer to the Reference Guide in the HyperWorks help.
Common HyperMesh Tcl Commands
hm_answernext
Force an answer to the next * command hm_answernext "yes"
*deletemodel
hm_blockmessages Inform HyperMesh whether or not messages should be displayed in header message bar
hm_createmark
Places entities on a mark based on user-supplied options
hm_elemlist Return list of element ids for passed component id hm_entityinfo Get information about entities in current model hm_entitylist
Get list of names or IDs of all entities of the requested type in current model
hm_entitymaxid Return maximum ID in use for an entity type hm_errormessage Display error message in header message bar hm_getclosestnode Return ID of closest node to point x y z
hm_getentityvalue
Get information for an entity using the HyperMesh template interface
hm_getfilename Get filename from user using HyperMesh file panel hm_getfloat Get floating point value from user using HyperMesh
panel
hm_getint Get integer value from user using HyperMesh panel hm_getmark Get ids for passed entity type on passed mark mask hm_getstring Get text string from user using HyperMesh panel hm_info Get general information about HyperMesh
hm_markclear Clear IDs for entity type from passed mark mask hm_nodelist Get list of node IDs for passed element
hm_nodevalue Get XYZ values for passed node ID
hm_usermessage Display message in HyperMesh header message bar
Using the Command Window
The first step in learning to integrate Tcl scripts into the HyperMesh environment is to learn how to launch scripts from the HyperMesh interface. An interactive Command Window is provided and can be access through the View menu. This
Chapter 4: Using Tcl to Control the HyperMesh Session
launches the Tk Console (TkCon) which is an interactive console which comes with Tk.
The Command Window
In the Command Window, users can evaluate any command that can be issued in Tcl or in HyperMesh through Tcl. Let’s examine a few commands. General Unix command such as ls, pwd, and cd can be used within the Command Window. The ls command will return the directory contents, the pwd command will return the current working directory, and the cd command allows users to change directories.
In addition to general UNIX commands, general and HyperMesh specific Tcl commands can be entered. For example, let’s use the HyperMesh specific Tcl command hm_info with the following options:
hm_info –appinfo SPECIFIEDPATH TEMPLATES_DIR
The above command with the provided options will return the current template directory. Any command that can be issued in Tcl or in HyperMesh through the Tcl command layer can be entered at the Command Window prompt and it will be evaluated. This capability provides the automation tool developer an easy means of testing a concept before writing the full procedure.
The Command Window also provides the ability to run Tcl scripts by either using the source command or using the File/Load Menu option. When using the source command, the complete path and filename needs to be given (unless the file is located in the directory the user is currently in within the Command Window).
source C:/temp/my_macro.tcl
The other option is to use the File/Load Menu. This menu is available in the Command Window by right clicking in the Command Window (shown below).
You can also save the session contents in the Command Window using the File/Save Menu option.
Chapter 4: Using Tcl to Control the HyperMesh Session
The Command Window Load Menu
Tcl scripts can also be run in HyperMesh by creating a button on the Utility menu User page. As was shown in Chapter 2, when creating a button for a Tcl script, the EvalTcl basic macro will need to be referenced in the
*createbutton() command. In the examples and exercises following, we will be using this macro to add buttons to the User page for the Tcl scripts that will be written.
Example 4.1: Using the Command Window
The purpose of this example is to become familiar with using the Command Window for developing in Tcl. In this example, HyperMesh Tcl and core Tcl commands, will be used in the Command Window to determine the number of elements in a component collector for a pre-defined HyperMesh model.
The following commands are used in this exercise:
Modified HyperMesh commands:
• *createmark()
HyperMesh Tcl commands
• hm_info
• hm_getmark Core Tcl commands
• list
• llength
• set
• source
Step 1: Launch the Command Window from HyperMesh
1. Open HyperMesh.2. Go to the View menu and select Command Window.
Chapter 4: Using Tcl to Control the HyperMesh Session
Step 2: Run operating system commands from the Command Window
Run a couple operating system commands to become familiar with entering commands and getting the output.
1. Run the command pwd.
The present working directory is returned.
2. Run the command ls
A list of the present working directory’s contents is returned.
Step 3: Run HyperMesh Tcl and core Tcl commands from the Command Window
1. Run the command set a [list 1 2 3 4 5]
A Tcl list variable named “a” is created and values 1-5 are added to this list.
2. Run the command set a_length [llength $a]
The length of the list “a” is set to the variable a_length.
Step 4: Retrieve the HyperMesh file c_channel-tcl_vector.hm Step 5: Create a buffer (mark) for the elements in the
component upper
Create a mark which contains all the elements in the component upper using the “by comp name” option in the *createmark command. In the Command Window, type the following:
*createmark elems 1 “by comp name” “upper”
Step 6: Retrieve the element ids from the mark and store them in a Tcl list variable.
In order to get the elements ids stored in the mark, the hm_getmark command is used. This command returns the entity IDs of the passed entity type from the specified mark In the Command Window, type the following:
set elemIds [hm_getmark elems 1]
Step 7: Count the number of elements in the list and display the
result
Chapter 4: Using Tcl to Control the HyperMesh Session
By using the llength Tcl command, the number of entities in the list elemIds can be found.
set numElems [llength $elemIds]
In the Command Window the value of 390 is returned, which is the number of elements in the component collector upper.
Step 8: Display the element count result
Using the puts command, we can print the output of a variable to the Command Window.
puts $numElems
Again the value returned is 390 which is the number of elements in the component collector upper.
Step 9: Verify the returned number of elements is the same number reported in HyperMesh’s Count panel.
1. On the Tool page, enter the count panel, FE entities subpanel.
2. Switch the entity selector to comps.
3. Select comps >> upper.
4. Click select to complete the selections.
5. Click selected.
6. Notice in the elems field is the number 390.
7. Click return to exit the count panel.
Step 10: Save the executed commands to a file
1. In the Command Window, right click and select File >> Save >> History.
2. For File name type command_window_ex.tcl.
3. In a text editor, open the file command_window_ex.tcl and verify it contains all of the commands you typed in the Command Window.
Step 11: Load the command_window_ex.tcl file into the Command Window.
1. Right click in the Command Window and select File >> Load File.
2. Select the command_window_ex.tcl file.
“390” is returned.
Chapter 4: Using Tcl to Control the HyperMesh Session
This example is complete. You can close the HyperMesh session.
Process to Create a Tcl HyperMesh Macro
1. Define the task.
2. Delete the existing command.cmf file. This file is located in either the start-in directory or the current working directory.
3. Perform the operations in HyperMesh that the script should run.
4. Extract the commands from the command.cmf
5. Create a Tcl script by converting the commands to Tcl format and modifying as necessary (this includes adding additional Tcl commands) 6. Create a new Utility menu macro that runs a Tcl script.
7. Add macro button using *createbutton that calls the macro created in Step 6 with the appropriate Tcl script filename.
8. Reload the current .mac file into HyperMesh to load the modified userpage.mac.
9. Test the macro.
This process is nearly identical to developing a HyperMesh Basic macro. The only differences are that the HyperMesh commands must be converted to Tcl format and that Tcl core commands are allowed to introduce control logic to the automation tools.
Example 4.2: Automate Creating Forces with a User Specified Magnitude
In this example, we will go through the general process for creating HyperMesh Tcl scripts. The script will automate the creating of forces with a user defined magnitude.
The following commands are used in this example:
Modified and added HyperMesh commands:
• *createmark
• *clearmark
HyperMesh Tcl commands:
• hm_getfloat Core Tcl commands:
• set
Step 1: Define the task to be automated.
Chapter 4: Using Tcl to Control the HyperMesh Session
1. Create a load collector named forces.
2. Request the user to select the nodes on which to apply a force.
3. Request the user to specify the magnitude of the forces to be created.
4. Create the forces and organize them into the forces collector.
Step 2: Delete the command.cmf file from your working directory.
Every command executed in HyperMesh is recorded in the command.cmf file.
To view only the task’s commands, it is suggested you delete the command.cmf file before doing the task. After deleting this file, the file is automatically
recreated when more commands are executed in HyperMesh.
Steps 3-5: Do the task in HyperMesh to capture its commands to the command.cmf file.
Step 3: Retrieve the file c_channel-tcl_vector.hm
1. Open HyperMesh.2. From File > Open, select the file c_channel-tcl_vector.hm
Step 4: Create a load collector.
1. Click the Model tab in the tab or go to the menu bar and select View >
Browsers > HyperMesh > Model.
2. Right-click in the white blank area and from the pop-up menu, select Create > Load Collector..
3. For Name, type forces.
4. Select any color for Color.
5. Verify that there is a check mark next to Close dialog upon creation.
6. Click Create to create the load collector.
Step 5: Create a force on the beam
1. On the Analysis page, enter the Forces panel.
2. With the nodes selector active, select any node.
3. For magnitude =, type 23.
4. For the direction selector, select the z-axis.
5. Toggle from magnitude % = to uniform size =.
6. Create the force.
7. Return to the main menu.
8. Keep this HyperMesh session open for steps later in this example.
Chapter 4: Using Tcl to Control the HyperMesh Session
Step 6: Copy the task’s commands in the command.cmf file and paste them to the create_force.tcl file.
1. Open a text editor and create a new text file named create_force.tcl.
Save the file to your HyperMesh working directory (My Documents on Windows).
2. From your HyperMesh working directory, open the command.cmf file.
3. Locate the following four commands at or near the end of the file.
*collectorcreateonly(loadcols, “forces”, “”, 7)
*loadsize(1,15,0,1)
*createmark(nodes,1) 3237
*loadcreateonentity(nodes,1,1,1,0,0,23,0,0,23,0,0,0,0,0) 4. Copy these commands and add them to the text file create_force.tcl
Steps 7-9 Modify and add to the script commands as necessary.
Step 7: Modify the code so it is in Tcl syntax
To modify the code so that it is in the appropriate Tcl syntax, parentheses and commas need to be replaced with a blank space. This results in the following four lines:
*collectorcreate loadcols “forces” “” 7
*loadsize 1 15 0 1
*createmark nodes 1 3237
*loadcreateonentity nodes 1 1 1 0 0 23 0 0 23 0 0 0 0 0
Step 8: Allow the user to select nodes on which to apply a force.
Here we are updating the code by adding the *clearmark command and replacing the *createmark command with *createmarkpanel. The
*clearmark command clears the node ids that are currently in the mark (if any are currently there). The *createmarkpanel command is used to get user selected nodes using a HyperMesh panel and store them in the buffer.
1. Before the *createmark command, add the following line which clears the node ids currently in mark 1.
*clearmark nodes 1
2. Modify the *createmark command to allow users to select the nodes using a HyperMesh panel and store them in the buffer.
Chapter 4: Using Tcl to Control the HyperMesh Session
*createmarkpanel nodes 1 “Select nodes”
Step 9: Allow the user to specify a force magnitude.
Using the hm_getfloat command, the user can enter a value for the
magnitude and then using the set command it can be stored as a variable. The variable can then be substituted for the hard coded force magnitude.
1. Get a force magnitude from the user using a HyperMesh panel and store it in a variable. Enter the following line after the *createmarkpanel command.
set mag_val [hm_getfloat “Magnitude =” “Enter the force magnitude”]
2. Substitute the hard coded force magnitude with the variable mag_val.
*loadcreateonentity nodes 1 1 1 0 0 $mag_val 0 0 $mag_val 0 0 0 0 0
Step 10: Review the script to see if it looks similar to the
following:
*collectorcreate loadcols “forces” “” 7
*loadsize 1 15 0 1
*clearmark nodes 1
*createmarkpanel nodes 1 “Select nodes”
set mag_val [hm_getfloat “Magnitude =” “Enter the force magnitude”]
*loadcreateonentity nodes 1 1 1 0 0 $mag_val 0 0 $mag_val 0 0 0 0 0
Step 11: Test the script by running it from the command window
1. Go to the currently open HyperMesh session.2. Open the file c_channel-tcl_vector.hm.
This refreshes the HyperMesh database. The load collector and forces you created earlier no longer exist.
3. Go to the View menu and select Command Window.
4. In the Command Window, type the following and then press Enter:
source create_force.tcl
A HyperMesh panel with a nodes selector appears.
5. Select node(s) in any manner you wish.
6. Click proceed to continue the script’s task.
A HyperMesh panel with an input field for the force magnitude appears.
7. For Magnitude =, type any number.
8. Click proceed to continue the script’s task.
The force(s) are created.
Chapter 4: Using Tcl to Control the HyperMesh Session
Steps 12-14 Test the script from a Utility tab button.
Step 12: Create a button on the Utility tab’s User page.
1. In your HyperMesh working directory, open the file userpage.mac.
If this file does not already exist, create a text file named userpage.mac.
2. On the next blank line from the top of the file, type the following
*createbutton line:
*createbutton(5, “Create Force”, -1, 0, 10, YELLOW,
“Create a force on selected nodes”, EvalTcl,
“create_force.tcl”) 3. Save the userpage.mac file.