Attention: Here be dragons

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Upgrading from Redot 4.0 to Redot 4.1

For most games and apps made with 4.0, it should be relatively safe to migrate to 4.1. This page intends to cover everything you need to pay attention to when migrating your project.

Breaking changes

If you are migrating from 4.0 to 4.1, the breaking changes listed here might affect you. Changes are grouped by areas/systems.

Warning

The GDExtension API completely breaks compatibility in 4.1, so it's not included in the table below. See the Updating your GDExtension for 4.1 section for more information.

This article indicates whether each breaking change affects GDScript and whether the C# breaking change is binary compatible or source compatible:

• Binary compatible - Existing binaries will load and execute successfully without recompilation, and the run-time behavior won't change.

• Source compatible - Source code will compile successfully without changes when upgrading Redot.

Core

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
Basis
Method looking_at adds a new use_model_front optional parameter	✔️	✔️	✔️	GH-76082
Object
Method get_meta_list changes return type from PackedStringArray to Array[StringName]	✔️	❌	❌	GH-76418
Transform3D
Method looking_at adds a new use_model_front optional parameter	✔️	✔️	✔️	GH-76082
UndoRedo
Method create_action adds a new backward_undo_ops optional parameter	✔️	✔️	✔️	GH-76688
WorkerThreadPool
Method wait_for_task_completion changes return type from void to Error	✔️	❌	✔️	GH-77143

Animation

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
AnimationNode
Method _process adds a new test_only parameter	❌	❌	❌	GH-75759
Method blend_input adds a new test_only optional parameter	✔️	✔️	✔️	GH-75759
Method blend_node adds a new test_only optional parameter	✔️	✔️	✔️	GH-75759
AnimationNodeStateMachinePlayback
Method get_travel_path changes return type from PackedStringArray to Array[StringName]	✔️	❌	❌	GH-76418

2D nodes

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
PathFollow2D
Property lookahead removed	❌	❌	❌	GH-72842

3D nodes

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
Geometry3D
Method segment_intersects_convex changes planes parameter type from untyped Array to Array[Plane]	✔️	✔️	❌	GH-76418
MeshInstance3D
Method create_multiple_convex_collisions adds a new settings optional parameter	✔️	✔️	✔️	GH-72152
Node3D
Method look_at adds a new use_model_front optional parameter	✔️	✔️	✔️	GH-76082
Method look_at_from_position adds a new use_model_front optional parameter	✔️	✔️	✔️	GH-76082

GUI nodes

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
CodeEdit
Method add_code_completion_option adds a new location optional parameter	✔️	✔️	✔️	GH-75746
RichTextLabel
Method push_list adds a new bullet optional parameter	✔️	✔️	✔️	GH-75017
Method push_paragraph adds a new justification_flags optional parameter	✔️	✔️	✔️	GH-75250
Method push_paragraph adds a new tab_stops optional parameter	✔️	✔️	✔️	GH-76401
Tree
Method edit_selected adds a new force_edit optional parameter	✔️	✔️	✔️	GH-76794

Physics

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
Area2D
Property priority changes type from float to int	❌	❌	❌	GH-72749
Area3D
Property priority changes type from float to int	❌	❌	❌	GH-72749
PhysicsDirectSpaceState2D
Method collide_shape changes return type from Array[PackedVector2Array] to Array[Vector2]	❌	❌	❌	GH-75260
PhysicsDirectSpaceState3D
Method collide_shape changes return type from Array[PackedVector3Array] to Array[Vector3]	❌	❌	❌	GH-75260

Rendering

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
RDShaderFile
Method get_version_list changes return type from PackedStringArray to Array[StringName]	✔️	❌	❌	GH-76418
RenderingDevice
Method draw_list_begin changes storage_textures parameter type from untyped Array to Array[RID]	✔️	✔️	❌	GH-76418
RenderingServer
Method global_shader_parameter_get_list changes return type from PackedStringArray to Array[StringName]	✔️	❌	❌	GH-76418
SurfaceTool
Method add_triangle_fan changes tangents parameter type from untyped Array to Array[Plane]	✔️	✔️	❌	GH-76418

Navigation

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
NavigationAgent2D
Method set_velocity replaced with velocity property	✔️	❌	❌	GH-69988
Property time_horizon split into time_horizon_agents and time_horizon_obstacles	❌	❌	❌	GH-69988
NavigationAgent3D
Property agent_height_offset renamed to path_height_offset	❌	❌	❌	GH-69988
Property ignore_y removed	❌	❌	❌	GH-69988
Method set_velocity replaced with velocity property	✔️	❌	❌	GH-69988
Property time_horizon split into time_horizon_agents and time_horizon_obstacles	❌	❌	❌	GH-69988
NavigationObstacle2D
Property estimate_radius removed	❌	❌	❌	GH-69988
Method get_rid renamed to get_agent_rid	❌	❌	❌	GH-69988
NavigationObstacle3D
Property estimate_radius removed	❌	❌	❌	GH-69988
Method get_rid renamed to get_agent_rid	❌	❌	❌	GH-69988
NavigationServer2D
Method agent_set_callback renamed to agent_set_avoidance_callback	❌	❌	❌	GH-69988
Method agent_set_target_velocity removed	❌	❌	❌	GH-69988
Method agent_set_time_horizon split into agent_set_time_horizon_agents and agent_set_time_horizon_obstacles	❌	❌	❌	GH-69988
NavigationServer3D
Method agent_set_callback renamed to agent_set_avoidance_callback	❌	❌	❌	GH-69988
Method agent_set_target_velocity removed	❌	❌	❌	GH-69988
Method agent_set_time_horizon split into agent_set_time_horizon_agents and agent_set_time_horizon_obstacles	❌	❌	❌	GH-69988

Networking

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
WebRTCPeerConnectionExtension
Method _create_data_channel changes return type from Object to WebRTCDataChannel	✔️	❌	✔️	GH-78237

Editor plugins

Change	GDScript Compatible	C# Binary Compatible	C# Source Compatible	Introduced
AnimationTrackEditPlugin
Type AnimationTrackEditPlugin removed	❌	❌	❌	GH-76413
EditorInterface
Type EditorInterface changes inheritance from Node to Object	✔️	❌	❌	GH-76176
Method set_movie_maker_enabled replaced with movie_maker_enabled property	✔️	❌	❌	GH-76176
Method is_movie_maker_enabled replaced with movie_maker_enabled property	✔️	❌	❌	GH-76176
EditorResourcePreviewGenerator
Method _generate adds a new metadata parameter	❌	❌	❌	GH-64628
Method _generate_from_path adds a new metadata parameter	❌	❌	❌	GH-64628
EditorUndoRedoManager
Method create_action adds a new backward_undo_ops optional parameter	✔️	✔️	✔️	GH-76688

Behavior changes

In 4.1 some behavior changes have been introduced, which might require you to adjust your project.

Change	Introduced
SubViewportContainer
When input events should reach SubViewports and their children, SubViewportContainer.mouse_filter now needs to be MOUSE_FILTER_STOP or MOUSE_FILTER_PASS. See GH-79271 for details.	GH-57894
Multiple layered SubViewportContainer nodes, that should all receive mouse input events, now need to be replaced by Area2D nodes. See GH-79128 for details.	GH-57894
Viewport
Viewport nodes, that have Physics Picking enabled, now automatically set InputEvents as handled. See GH-79897 for workarounds.	GH-77595

Updating your GDExtension for 4.1

GDExtension is still in beta. Until it's marked as stable, compatibility may break when upgrading to a new minor version of Redot.

In order to fix a serious bug, in Redot 4.1 we had to break binary compatibility in a big way and source compatibility in a small way.

This means that GDExtensions made for Redot 4.0 will need to be recompiled for Redot 4.1 (using the 4.1 branch of godot-cpp), with a small change to their source code.

In Redot 4.0, your "entry_symbol" function looks something like this:

GDExtensionBool GDE_EXPORT example_library_init(const GDExtensionInterface *p_interface, const GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization) {
    godot::GDExtensionBinding::InitObject init_obj(p_interface, p_library, r_initialization);

    init_obj.register_initializer(initialize_example_module);
    init_obj.register_terminator(uninitialize_example_module);
    init_obj.set_minimum_library_initialization_level(MODULE_INITIALIZATION_LEVEL_SCENE);

    return init_obj.init();
}

However, for Redot 4.1, it should look like:

GDExtensionBool GDE_EXPORT example_library_init(GDExtensionInterfaceGetProcAddress p_get_proc_address, const GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization) {
    godot::GDExtensionBinding::InitObject init_obj(p_get_proc_address, p_library, r_initialization);

    init_obj.register_initializer(initialize_example_module);
    init_obj.register_terminator(uninitialize_example_module);
    init_obj.set_minimum_library_initialization_level(MODULE_INITIALIZATION_LEVEL_SCENE);

    return init_obj.init();
}

There are two small changes:

1. The first argument changes from const GDExtensionInterface *p_interface to GDExtensionInterfaceGetProcAddress p_get_proc_address

2. The constructor for the init_obj variable now receives p_get_proc_address as its first parameter

You also need to add an extra compatibility_minimum line to your .gdextension file, so that it looks something like:

[configuration]

entry_symbol = "example_library_init"
compatibility_minimum = 4.1

This lets Redot know that your GDExtension has been updated and is safe to load in Redot 4.1.