Terminology

SpriteBreaker: the main component added to GameObject that facilitates generation of shards.

Shards: objects generated by SpriteBreaker meant to look like fragments of the original sprite.

Sprite Breaker Data: contains actual shapes of the polygons used to create shards. Can be contained in SpriteBreaker component, or saved and reused as an asset of type SpriteBreakerDataAsset.

Sprite Breaker Data Asset: contains Sprite Breaker Data in a format that can be stored in project Assets. Can be used to reuse the same shard shapes between multiple different sprites, or for setting the same starting shape for radial shatter generator.

Sprite Breaker Editor: A tool included with this package, for manually defining and editing shard shapes in Sprite Breaker Data.

Sprite Breaker Component Inspector

Sprite: if this is assigned to a Sprite asset, SpriteBreaker will use this sprite instead of looking for SpriteRenderer component on this GameObject.

Shard Prototype: optional prefab for a shard object. If you want your shards to have other scripts or behaviors attached on spawn, create a prefab and assign it to this field.

Shards Parent: if you want shards to be parented to a transform other than this GameObject, set it here.

Break on Awake: call Break() when this GameObject is added to the scene.

Break Button: calls Break() method on the component. Generates shards according to current Breaker Data.

Clear Button: calls Clear() method on the component. Destroys any created shards.

Breaker Data / Edit Data: click this button to open Sprite Breaker Editor to edit current shards shapes.

Breaker Data / Clear Data: deletes current Breaker Data.

Breaker Data / Asset / Load Data: if Sprite Breaker Data Asset is assigned, current Breaker Data will be replaced with that from the asset.

Breaker Data / Asset / Save to (or Replace) Asset: saves current data to a new Sprite Breaker Data Asset, or replaces/overwrites the one in the field.

Generate / Seed: if zero, a random seed will be used for generating shatter effect each time, otherwise uses the provided seed.

Generate / Use: Starting shape for generating shards.
Quad - use basic full quad
Data - use current data as the starting point
Asset - use assigned asset (if assigned) as the starting point

Generate / Randomness: the amount of initial shard shape irregularity in the generation algorithm.

Generate / Angle: starting angle for radial shards.

Generate / Spacing: initial spacing in degrees between shards. Higher number = fewer shards.

Generate / Frequency: how often to subdivide each radial shard. Higher number = more subdivisions.

Generate / Origin: center of the generated shards on the sprite.

Generate / Preview: shows what Breaker Data will look like. You can click on the preview to change Origin.

Generate / Generate Shards: click to replace current Breaker Data with generated polygons.

Appearance / Keep Shards Color Updated: if checked, shards material's _Color property will be updated each frame with SpriteBreaker.shardsColor value.

Appearance / Shadow Casting Mode: shards MeshRenderer.castShadows will be set to this value on spawn, unless using shard prefab with MeshRenderer.

Appearance / Receive Shadows: shards MeshRenderer.receiveShadows will be set to this value on spawn, unless using shard prefab with MeshRenderer.

Appearance / Disable SpriteRenderer On Break: if there's a SpriteRenderer attached to this GameObject, it will be disabled when shards are spawned, and re-enabled if SpriteBreaker component is reset.

Appearance / Draw Editor Gizmos: draw Breaker Data polygons in the editor.

Simulation / Time To Live: total lifetime for all the shards in seconds.

Simulation / Fade After: shards will begin to fade (using material _Color property) after this number of seconds.

Simulation / End Action: what happens after Time To Live seconds elapses.
Destroy Object - destroy the GameObject that SpriteBreaker is attached to
Destroy Parent - destroy shards parent transform GameObject if set, otherwise destroy this transform's parent
Deactivate Shards - each shards' GameObject will be setActive to false.
Reset - destroy shards and re-enable SpriteRenderer.
Clear Data And Reset - destroy shards, re-enable SpriteRenderer, and delete Breaker Data.
Restart - destroy shards, re-create shards and restart simulation.
Nothing - do nothing.

Simulation / Physics: type of simulation to run on generated shards. Affects what additional components are created on shards.
Collider 2D - use 2D physics. Creates PolygonCollider2D and RigidBody2D.
Collider 3D - use 3D physics. Creates MeshCollider and RigidBody.
Fake Physics - simulates shards falling down using internal Update method. No colliders.

Simulation / Collider Thickness: if Collider 3D is selected, this will define the collision mesh's thickness used by MeshCollider.

Simulation / Mass Multiplier: the physics mass of the simulated shard is its polygon's area multiplied by this number.

Simulation / Initial Impulse: initial impulse applied to each shard:
Radial - shard is pushed away from the sprite's center
Linear - shard is pushed in X,Y, or Z direction
Rotational - shard's initial rotational velocity

Events / OnShardCreated( GameObject, SpriteBreakerPolygon, SpriteBreaker ): emitted for each created shard. Can be used for additional initialization. GameObject is the shard itself, SpriteBreakerPolygon contains data used to spawn this shard from Breaker Data, and SpriteBreaker is this component.

Events / OnTimeToLiveExpired( GameObject ): emitted on each shard when Simulation / Time To Live has elapsed.

Advanced / CSG Upscale: Used by internal algorithm performing CSG (polygon cutting and Booleans) to premultiply points coordinates.

Advanced / CSG Epsilon: Epsilon precision value used during CSG. Represents 10 to the -X power (or 10e-X).

Shards Shape Editor

Sprite Breaker Editor is used to manually edit the breaker data polygons used to create shards. It opens in a floating window, and displays the sprite from SpriteRenderer component attached to this GameObject, or Sprite from SpriteBreaker component, if it's overridden. On top of the sprite there can be one or more polygons, representing the shards that will be created on break. If the current sprite breaker data is empty, this will be populated from sprite's outline shape.

Inside the window use mouse middle or right button to pan, mouse wheel to zoom, and left mouse button to select points and polygons.

On top of the window there are three buttons that toggle current mode - Create, Edit, and Cut.

Reset Sprite button on the far top right will reset the current sprite data to sprite's outline shape.

Sprite Breaker Editor respects Unity's undo system.

Create mode

Clicking in the editor will begin a new polygon. Place three or more points and right click, or hit Enter or Escape to finish. Hover mouse near an existing point to snap to it while creating.

Press Tab while adding points to toggle polygon direction.

Edit mode

Switching to Edit will display an additional toggle to the right, between Move, Rotate, and Scale.

Clicking on a point or a polygon will select it. Shift + Click will select multiple. Shift + Click + drag in empty space will begin selecting using a marquee. To deselect, click in empty space.

Dragging a point or a polygon will either move, rotate, or scale it based on what's currently selected on top.

Holding Shift during move or scale restricts moving along one axis. During Rotate it will snap to 15 deg increments.

Keyboard arrow keys will move selected points up, down, left, and right. Hold Shift to move faster.

Inside each polygon there's a "+" shaped icon. It represents the pivot point of the shard that will be created. It can be moved around relative to the polygon.

Right-clicking on a polygon will bring up its properties:

• Enabled: whether a shard will be created for this polygon
• Active: whether the shard GameObject will be active
• Physics: participate in simulation
• Name: GameObject name assigned to the shard
• Sorting Order: MeshRenderer sortingOrder is set to the sortingOrder of the SpriteRenderer + this value
• Z Offset: shard's transform z offset
• Pivot: shard's pivot relative to the polygon
• Tag: shard GameObject tag
• Float Value: passed to OnShardCreated callback in SpriteBreakerPolygon class
• String Value: passed to OnShardCreated callback in SpriteBreakerPolygon class

Double clicking a polygon will isolate it for editing. This can be helpful when there are many polygons nearby.

Select two or more overlapping polygons to perform Combine, Subtract, and Intersect boolean operations. The buttons will appear in the tool bar area on top.

Hold Control and click on a polygon edge to insert a point. Clicking will place this point, and will start inserting another. Press Tab or Shift+Tab to change direction/cycle though segments. Enter, Escape, or right click to finish.

Cut mode:

Click in empty space or on a point to start defining a cutting line. Place two or more points and right click, or hit Enter or Escape to finish. Editor will split intersecting polygons using this line. If you're working with an isolated polygon, only that polygon will be affected.

Note that you can't make straight up holes in polygons. You can fake them however.