When to use scenes versus scripts

    Each system’s capabilities are different as a result. Scenes can define how an extended class initializes, but not what its behavior actually is. Scenes are often used in conjunction with a script so that the scene acts as an extension of the scripts declarative code.

    It is possible to completely define a scenes’ contents using a script alone. This is, in essence, what the Godot Editor does, only in the C++ constructor of its objects.

    But, choosing which one to use can be a dilemma. Creating script instances is identical to creating in-engine classes whereas handling scenes requires a change in API:

    Also, scripts will operate a little slower than scenes due to the speed differences between engine and script code. The larger and more complex the node, the more reason there is to build it as a scene.

    In some cases, a user can register a script as a new type within the editor itself. This displays it as a new type in the node or resource creation dialog with an optional icon. In these cases, the user’s ability to use the script is much more streamlined. Rather than having to…

    1. Know the base type of the script they would like to use.

    2. Create an instance of that base type.

    3. Add the script to the node.

      1. (Drag-n-drop method)

        1. Find the script in the FileSystem dock.

        2. Drag and drop the script onto the node in the Scene dock.

    With a registered script, the scripted type instead becomes a creation option like the other nodes and resources in the system. One need not do any of the above work. The creation dialog even has a search bar to look up the type by name.

    There are two systems for registering types…

    Both methodologies add names to the creation dialog, but script classes, in particular, also allow for users to access the typename without loading the script resource. Creating instances and accessing constants or static methods is viable from anywhere.

    With features like these, one may wish their type to be a script without a scene due to the ease of use it grants users. Those developing plugins or creating in-house tools for designers to use will find an easier time of things this way.

    On the downside, it also means having to use largely imperative programming.

    One last aspect to consider when choosing scenes and scripts is execution speed.

    As the size of objects increases, the scripts’ necessary size to create and initialize them grows much larger. Creating node hierarchies demonstrates this. Each Node’s logic could be several hundred lines of code in length.

    The code example below creates a new , changes its name, assigns a script to it, sets its future parent as its owner so it gets saved to disk along with it, and finally adds it as a child of the node:

    GDScript   C#

    Script code like this is much slower than engine-side C++ code. Each instruction makes a call to the scripting API which leads to many “lookups” on the back-end to find the logic to execute.

    Scenes help to avoid this performance issue. , the base type that scenes inherit from, defines resources that use serialized data to create objects. The engine can process scenes in batches on the back-end and provide much better performance than scripts.

    In the end, the best approach is to consider the following:

    • If one wishes to create a basic tool that is going to be re-used in several different projects and which people of all skill levels will likely use (including those who don’t label themselves as “programmers”), then chances are that it should probably be a script, likely one with a custom name/icon.

    • GDScript