Lua Introduction

Callback Functions

If you open your script in the Script Editor you can see that there are already the most important lines of code. These are the so called callback functions which are called by Candera.

Init(self, id)

The Init function gets called before the first Update call or when a script component is enabled for the first time. At this point all script instances have been created and optionally initialized via Awake, so scripts are ready to interact with each other to perform final initializations before the Update loop starts.

Update(self, id)

Called every render frame if the script component is enabled. Update is the commonly used function to implement application behavior.

Note: if you use one of the callback functions or if you want to make an own function public then don't forget to add them to the public table! (see next paragraph)

return{}

It returns the public interface as table. Variables that have been exposed via the public interface table, and are either of type integer, float, string, or boolean, are automatically displayed in SceneComposer's GUI. In the SceneComposer this variables can be edited and are saved/loaded with the scene. Functions in the return section are not displayed in SceneComposer's GUI but they are public and can get called by another script or by Candera (see "Callback Functions").

To provide access to variables of the public table of the instance, the table is passed in the function parameter 'self' in all functions that are being called by Candera's script system. So if you define a variable in the public table you can use it in any functions of this script via "self.yourVariable".

Save and Start a Script

To validate your script press %<F8%> or choose "Script" - "Validate Script" from the menu.

When the script has been validated and there are no errors, you can press the start button to start the execution of the script system and stop it with the second button.

Candera Logging

To check whether your script crashes during runtime or not you can see errors or further information in the Candera Logging panel. If this panel is not activated go to View -> Output -> and check Candera Logging

Tip: Candera Logging is also very useful to test individual parts of your code like if-cases or loops via:

Candera.LogInfo(message)