====== Meta Command Creation ======

==== Combining Pipeline Scripts into a Meta-Command ====

This is an example for creating a meta-command in Visual3D.

1. Suppose you have a pipeline script that generates a metric or some sort of result.

2. Suppose also, that you have a second script that needs the result of the first script.

3. Finally suppose you are tired of calling 2 scripts and want to do it all at once.

\\
Here is an extremely simplistic example. Script1 below prompts you to enter a number, and script2 prints it out.

(Note: Naturally, these scripts will not run separated like this – the input value would have to be stored somewhere. Using a Call_Script command also fails because it does not pass data.)

\\


<code>
 Script1.v3s:  
 Prompt_For_Pipeline_Parameter_Value  
 /PIPELINE_PARAMETER_NAME=the_input_number  
 /PROMPT=Pick a number!  
 ;  
</code>

\\


<code>
Script2.v3s: 
 Set_Pipeline_Parameter  
 /PARAMETER_NAME=output_text  
 /PARAMETER_VALUE_PREFIX=Your number was...  
 /PARAMETER_VALUE=::the_input_number  
 ;  
</code>

Here is a process to modify the scripts so that they work together:\\


  - Convert the second script to a meta-command\\

  - Save the new meta-command in the proper Visual3D directory\\

  - Edit the first script to call the meta-command\\


\\
Edit **Script2.v3s** and change it to the following, and save it as **number_game.v3m**. //Note that the meta-command syntax is simply a few lines as a header, and then changing any input parameter names to match. For the syntax of the header see [[Visual3D:Documentation:Pipeline:Meta_Commands:Meta_Commands_Overview|Pipeline_Commands:Meta_Commands]].//

<code>
! BEGIN_META  
! META_CMD_NAME=number_game 
! META_PARAM= THE_NUM: string ::yes  
! END_META 


Set_Pipeline_Parameter 
/PARAMETER_NAME=output_text 
/PARAMETER_VALUE_PREFIX=Your number was... 
/PARAMETER_VALUE=::THE_NUM 
; 
  
</code>

Copy the file **number_game.v3m** to the meta-command directory: Possibly: C:\Program Files (x86)\Visual3D v5\ Plugins\Meta-Commands

\\
Edit **Script1.v3s** and change it to the following:

<code>
Prompt_For_Pipeline_Parameter_Value 
/PIPELINE_PARAMETER_NAME=the_input_number 
/PROMPT=Pick a number! 
; 
  
number_game 
/THE_NUM=::the_input_number 
;
 
</code>

That’s it. Restart Visual3D and run the new **script1.v3s**.

Note also that if you copy script1.v3s to C:\Program Files (x86)\Visual3D v5\Plugins\Scripts then the script will show up in the box on the workspace tab in Visual3D for easy access.