Sprite Slicing

Godot asset to slice 2D sprites.

Slicer2D is the main node and contains all the functionality to slice sprites.
Sliceable2D is the type of the object sliced by Slicer2D.

This document uses the format of the official Godot docs.

That is type name for variables and return_type name(type name) for functions.

The SlicingData datatype

SlicingData is the type which contains information of a sliced object. It contains the following fields:

class SlicingData:
	Sliceable2D object
	Vector2 global_enter
	Vector2 global_out
	int cut_number
	Array slices

object: the original sliced object, this reference might be invalidated by queue_free() if you configure the Slicer2D to destroy that object after the slices are created.
global_enter: global coordinate of the entry of the cut in the object.
global_out: global coordinate of the exit of the cut in the object.
cut_number: number of the actual cut.
slices: array of references to the slices generated by the processed slice.

Tip: you can use global_enter and global_out to create animations.

Method list

Array slice_world(Vector2 start, Vector2 end, int collision_layer = 0x7FFFFFFF, bool destroy = true)

Tries to find Sliceable2Ds to cut from start to end. Returns an Array of SlicingData one for each sliced object.

start: the start of the cut in global coordinates.
end: the end of the cut in global coordinates.
collision_layer: optional parameter to restrict the cut using a collision layer.
destroy: if true the object will be destroyed with queue_free() so only its slices are active.

SlicingData slice_one(Sliceable2D item, Vector2 start, Vector2 end, int collision_layer = 0x7FFFFFFF, bool destroy = true)

Does the same as slice_world but only cuts item if it is found in the cut.

Properties

Physics2DDirectSpaceState space_state

For advanced users. Assign a custom space state and it will be used to detect sliceable objects. That way you can isolate the interaction of a Slicer2D as the sliceable objects are identified using raycasts. Default value: null

float min_area.

Minimum approximate area. Default value: 0.01

float impulse_intensity

This value is multiplied to the force applied to the slices when you cut them. Default value: 100.0

Project Demo

The demo folder contains a basic demo showing the functionality of this asset. Open demo/TestScene.tscn and test the asset in action!

Assets

apple.png: CC-BY-SA 3.0

Asset usage

Copy Sliceable2D.gd and Slicer2D.gd to your game.
Add a Slicer2D node to your scene.

Sliceable2D

In order to create a sliceable object:

Create a new scene with a RigidBody2D as the root node.
Add a script to the RigidBody2D and put at the beginning of the script extends Sliceable2D
Add a Sprite node and add a texture.
Click on the RigidBody2D and check the inspector. In Script Variables you should see a field "Sprite Node". Click on it and select your Sprite.
Add a CollisionPolygon2D or a CollisionShape2D to your RigidBody2D.

Notes:

The order of the required children doesn't matter, they just need to exist. The only special requirement is defining the "Sprite Node" field in the inspector.
Collisions must fit the figure of the sprite because the slices are generated using the collision shapes.
The Sprite can have flip_h and flip_v enabled.
You can add as many collision shapes as you wish. I you use CollisionShape2D the supported Shape2D is: ConvexPolygonShape2D. In the future it will support CapsuleShape2D, CircleShape2D and RectangleShape2D too.
After a cut, the created slices will replace the node pointed by "Sprite Node" with a MeshInstance2D.
The Sliceable2D created by a cut will be reparented to the same parent of the original sliced object.

Advanced usage:

If you want to change the texture of a Sliceable2D just access the property texture of the "Sprite Node". Before the first cut you will access the Sprite you defined, and if you are accessing a sliced Sliceable2D you will be accessing the texture property of a MeshInstance2D. The node name of the original Sprite will be respected by the new MeshInstance2D so it is secure to access with the $ operator. Just keep in mind the new texture will be mapped based on the UV of the original texture.

You can define the following in your script to gain more control over the slicing process:

int cut_limit_val

If the cut_number is >= than cut_limit_val this object wont be sliced anymore. You can disable slicing on an object defining cut_limit_val with values of 0 or lower.

void _on_sprite_sliced(SlicingData data)

This function will be called on the sliced object (not the slices generated by the cut) and data will contain the information about the slicing of your object.

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travm / godot-sprite-slicing