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Developer Guide (Version 1.11)

Creating Custom Nodes in Script Canvas

Script Canvas uses the behavior context. The preferred way to expose functionality in Script Canvas is through behavior context bindings. Behavior context bindings make functionality available to any scripting solution (such as Lua) that also uses the behavior context. However, if you want to create Script Canvas–specific functionality or customized visual scripting experiences, you can use the Script Canvas custom node API.

If your gem provides custom Script Canvas nodes, you must specify a dependency on the Script Canvas Gem and configure Waf appropriately to compile the nodes. Functionality that you reflect through the behavior context requires no dependency on the Script Canvas Gem.

Custom nodes in Script Canvas take advantage of AZ Code Generator and boilerplate code. This reduces complexity and lets you focus on implementing the behavior of the node.

The following diagram shows the AZ Code Generator process for Script Canvas.


      AZ Code Generator and Script Canvas

In Step 1, AZ Code Generator processes MyNode.h and looks for code generation tags (source code location: dev\Gems\ScriptCanvas\Code\Include\ScriptCanvas\CodeGen\CodeGen.h). After processing, AZ Code Generator creates a file called MyNode.generated.h.

Note

You must include MyNode.generated.h in the MyNode.h file so that the preprocessor macro that AZ Code Generator produces is resolved by C++ during Step 3.

In Step 2, AZ Code Generator processes MyNode.h again, but this time produces a .cpp file.

Note

You must include MyNode.generated.cpp the in MyNode.cpp file. This ensures that the generated code can be compiled and has access to all the same #include declarations as those found in MyNode.cpp.

In Step 3, AZ Code Generator is finished and the build process continues as normal. MyNode.cpp is compiled and succeeds provided all the generated files are correct.