====Writing Your First ARDI Script====

Let's look a very common command - [[ardiscript:perspective|perspective]].

The command is used to move the camera to look at a given asset.

Using the documentation (in the link above), we find that perspective has a number of parameters. The most important is **target**, which is the name of the asset we would like to focus on.

So imagining we have a scene that contains an asset called 'Main Engine', we could have the following command...

<code xml>
<script>
    <perspective target="Main Engine"/>
</script>
</code>

This script will take control of the camera, move so that the Main Engine is visible, then end. 

===Running Local Scripts===

To run a local script, look in your Documents folder. You should find a folder named **Optrix/ARDI/**//<database-name>//**Scripts** (for example, if your database is called "Headquarters", it would be under Optrix/ARDI/Headquarters/Scripts)

Save the XML file to this folder. 

When you press F11 in ARDI-VE, you'll be prompted to choose from the available scripts. Scroll down to find the name of the file, then click it.

===Adding More Steps & Sequencing===

One of the keys to writing ARDI scripts is understanding the **control** functions. These control how your scripts move from one step to the next.

Normally, ARDI immediately moves from step-to-step. It doesn't wait for the previous step to complete before proceeding. This means that if you're performing a long-running task that you'd like the user to see, you need to interrupt the flow of steps.

^Function^Purpose^
|[[ardiscript:Block|block]]|Wait until all running functions have stopped|
|[[ardiscript:Pause|pause]]|Wait a given amount of time (default=1s)|
|[[ardiscript:WaitForClick|waitforclick]]|Wait until the user clicks the 'Next' button. An on-screen caption is optional|

So if we wanted to intoroduce someone to several components - the //Main Engine//, //Secondary Engine//, we could have the following script...

<code xml>
<script>
  <!-- Show the Main Engine-->
   <perspective target="Main Engine"/>
   <waitforclick caption="This is the main engine"/>

   <!-- Show the Secondary Engine-->   
   <perspective target="Secondary Engine"/>
   <waitforclick caption="This is the secondary engine"/>   
</script>
</code>

===Introducing Other Functions===

Now the main engine is made up of dozens of parts, and we'd like to highlight some of those components. 

You can access sub-components of assets by using a path.

For example, in this case we are going to highlight the //exhaust// on our main engine as part of our scripted tour.

<code xml>
<script>
   <perspective target="Main Engine"/>
   <waitforclick caption="This is the main engine"/>

   <!-- Show the Main Engine Exhaust, and remove the highlight when you're done -->
   <highlight target="Main Engine\*Exhaust"/>
   <waitforclick caption="This is the main engine"/>
   <unhighlight target="Main Engine\*Exhaust"/>
   
   <perspective target="Secondary Engine"/>
   <waitforclick caption="This is the secondary engine"/>   
</script>   
</code>

**Exhaust** is a component inside the Main Engine 3D model. By using the asterisk (*), we tell ARDI that we don't care where exactly the 'exhaust' object is, just that it must be //somewhere// under the Main Engine. 

The **[[ardiscript:highlightobject|highlight]]** step shown above is an example of a step that needs to be //removed// when you're done. **[[ardiscript:unhighlight|Unhighlight]]** performs this job. 

When a script terminates, it is //cleaned up//. This means that many behaviours - such as the Highlight shown above - will automatically be reversed when the script completes.