ANM2 Files

Those files are used to store animations. You can edit and create them with the official animation editor (available in the tools directory) or with Anm2ed, see the corresponding page for more informations.

Specification: https://www.reddit.com/r/themoddingofisaac/comments/377a9h/animations_explained/

Structure

• <AnimatedActor>
  • <Info />
  • <Content>
    • <Spritesheets>
      • <Spritesheet>
    • <Layers>
      • <Layer />
    • <Nulls>
      • <Null />
    • <Events>
      • <Event />
  • <Animations>
    • <Animation>
      • <RootAnimation>
        • <Frame />
      • <LayerAnimations>
        • <LayerAnimation>
          • <Frame />
      • <NullAnimations>
        • <NullAnimation>
          • <Frame />
      • <Triggers>
        • <Trigger />

"Info" Tag

General metadata for the file. It is an orphan tag.

Attribute-Name	Type	Description
CreatedBy	string
CreatedOn	string	A date in format M/D/Y h:m:s PM/AM
Version	int
Fps	int	The framerate of all animations.

"Content" Tag

Contains external references and their corresponding IDs.

Bug

File paths may be capitalized while the actual files are actually in lowercase.

"Spritesheet" Tag

Pairs a spritesheets with an ID.

Attribute-Name	Type	Description
Path	string	File path to the spritesheet, starting from gfx/.
Id	int

"Layer" Tag

Pairs a layer with a spritesheet and a name. Tags are ascending order of IDs.

Attribute-Name	Type	Description
Name	string
Id	int
SpritesheetId	int

"Null" Tag

Represents another in game object, for example in the "Pickup" animation of Isaac, a null layer is used to move the item Isaac raises above his head.

Attribute-Name	Type	Description
Name	string
Id	int

"Event" Tag

Trigger for an ingame action, like a sound or an attack.

Attribute-Name	Type	Description
Name	string
Id	int

"Animations" Tag

Attribute-Name	Type	Description
DefaultAnimation	string	The default animation's name.

"Animation" Tag

Attribute-Name	Type	Description
Name	string	A unique identifier for the animation.
FrameNum	int	The maximum duration of the animation (in frames).
Loop	bool	Possible values: ["true", "false"]

"RootAnimation" Tag

Transformations to every layers.

"LayerAnimation" Tag

Animations per layers, if a layer is not animated, the tag may be orphan. There must be one <LayerAnimation> per layer.

Attribute-Name	Type	Description
LayerId	int
Visible	bool	Possible values: ["true", "false"]

"NullAnimation" tag

An animation to apply to another object (see <Null>).

Attribute-Name	Type	Description
NullId	int
Visible	bool	Possible values: ["true", "false"]

"Frame" tag

Attribute-Name	Type	Description
XPosition	int	Default = 0
YPosition	int	Default = 0
Delay	int	The frame's duration in frames.
Visible	bool	Possible values: ["true", "false"]
XScale	int	The sprite's horizontal scale in percent. Negative values flip the sprite. Default = 100
YScale	int	The sprite's vertical scale in percent. Negative values flip the sprite. Default = 100
RedTint	int	Lower values makes the sprite less red (example). Should be between 0 and 255. Default = 255
GreenTint	int	Lower values makes the sprite less green (example). Should be between 0 and 255. Default = 255
BlueTint	int	Lower values makes the sprite less blue (example). Should be between 0 and 255. Default = 255
AlphaTint	int	Sprite's opacity. 255 is totally opaque, 0 is transparent.
RedShift	int	Makes the sprite more red (example). Should be between 0 and 255. Defalut = 0
GreenShift	int	Makes the sprite more green (example). Should be between 0 and 255. Defalut = 0
BlueShift	int	Makes the sprite more blue (example). Should be between 0 and 255. Defalut = 0
Rotation	int	Rotates the sprite clockwise. The value is in degrees.
Interpolated	bool	If set to true, the game will transition between values.

If the tag is child of <LayerAnimation> it may provide more attributes: | Attribute-Name | Type | Description | |:--|:--|:--| | XPivot | int | Sets a x coordinate for a "pin" where the layer can be rotated arround | | YPivot | int | Sets a y coordinate for a "pin" where the layer can be rotated arround | | XCrop | int | The x coordinate of the crop rectangle's top left vertex in the spritesheet. | | YCrop | int | The y coordinate of the crop rectangle's top left vertex in the spritesheet. | | Width | int | The width of the crop rectangle. | | Height | int | The heigth of the crop rectangle. |

"Triggers" Tag

Triggers for events. This tag may be orphan.

"Trigger" Tag

Attribute-Name	Type	Description
EventId	int
AtFrame	int

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Last update: July 14, 2026