ANCS (File Format)

The ANCS format defines character sets and animation sets in Metroid Prime 1 and 2. Starting in Metroid Prime 3, it was replaced by the CHAR and SAND formats. The extension stands for ANimation Character Set.

Format

Type	Name	Notes
u16	Version	Always 1.
Character Set	Character Set	Set of characters that share animation data.
Animation Set	Animation Set	Set of animations used by the characters in the character set.

Character Set

Type	Count	Name	Notes
u16	1	Version	Always 1.
u32	1	Character Count	Count of characters in this set.
Character	Character Count	Characters Array	Array of characters.

Character

Type	Count	Name	Notes	V1	V2	V4	V5	V10
u32	1	Character ID	Typically begins at 0 and increments by 1 on each successive character in the set.	✔	✔	✔	✔	✔
u16	1	Version	This can vary between different files/characters. Usually 5 or 6 in MP1 and 10 in MP2.	✔	✔	✔	✔	✔
string	1	Name	Name of the character. Not used by the game; was likely included for debugging purposes.	✔	✔	✔	✔	✔
Asset ID (CMDL)	1	Model ID	ID of the model used by this character.	✔	✔	✔	✔	✔
Asset ID (CSKR)	1	Skin ID	ID of the skin used by this character.	✔	✔	✔	✔	✔
Asset ID (CINF)	1	Skeleton ID	ID of the skeleton used by this character.	✔	✔	✔	✔	✔
u32	1	Animation Name Count	Count of animation names in the next array.	✔	✔	✔	✔	✔
Animation Name	Animation Name Count	Animation Name Array	Array of names of animations used by this character.	✔	✔	✔	✔	✔
PAS Database	1	PAS Database	Not much is known about how this data is used.	✔	✔	✔	✔	✔
Particle Resource Data	1	Particle Resource Data	List of particle assets being used by this character. This includes particles being used by attached effects as well as by animation events.	✔	✔	✔	✔	✔
u32	1	Unknown		✔	✔	✔	✔	✔
u32	1	Unknown		✖	✖	✖	✖	✔
u32	1	Animation AABB Count	Count of animation bounding boxes.	✖	✔	✔	✔	✔
Animation AABB	Animation AABB Count	Animation AABB Array	Array of animation bounding boxes for this character.	✖	✔	✔	✔	✔
u32	1	Effect Count	Count of attached effects.	✖	✔	✔	✔	✔
Effect	Effect Count	Effect Array	Effects attached to this character.	✖	✔	✔	✔	✔
Asset ID (CMDL)	1	Frozen Model	Overlay model that appears when the character is frozen with the Ice/Dark Beam.	✖	✖	✔	✔	✔
Asset ID (CSKR)	1	Frozen Skin	Skin for rigging the Frozen Model to the character's skeleton.	✖	✖	✔	✔	✔
u32	1	Animation Count	Count of animations used by this character.	✖	✖	✖	✔	✔
u32	Animation Count	Animation ID Map	Array of animation IDs. Indexing this array with the character-relative animation ID returns the animset-relative animation ID.	✖	✖	✖	✔	✔
Asset ID (CSPP)	1	Spatial Primitives ID	ID of the spatial primitives used by this character.	✖	✖	✖	✖	✔
u8	1	Unknown		✖	✖	✖	✖	✔
u32	1	Indexed Animation AABB Count	Count of indexed animation bounding boxes.	✖	✖	✖	✖	✔
Indexed Animation AABB	Indexed Animation AABB Count	Indexed Animation AABB Array	Unknown purpose.	✖	✖	✖	✖	✔

Animation Name

Type	Name	Notes	V1	V10
u32	Animation ID	Character-relative animation ID. Must be remapped via the Animation ID Map to access the corresponding animation in the animset.	✔	✔
string	Unknown	Always empty.	✔	✖
string	Animation Name	The name of the animation.	✔	✔

Particle Resource Data

Type	Count	Name	Notes	V5	V6	V10
u32	1	Generic Particle Count	Count of generic particle systems.	✔	✔	✔
Asset ID (PART)	Generic Particle Count	Generic Particle List	List of generic particle systems used by this character.	✔	✔	✔
u32	1	Swoosh Particle Count	Count of swoosh particle systems.	✔	✔	✔
Asset ID (SWHC)	Swoosh Particle Count	Swoosh Particle List	List of swoosh particle systems used by this character.	✔	✔	✔
u32	1	Unknown	Always 0.	✖	✔	✔
u32	1	Electric Particle Count	Count of electric particle systems.	✔	✔	✔
Asset ID (ELSC)	Electric Particle Count	Electric Particle List	List of electric particle systems used by this character.	✔	✔	✔
u32	1	Spawn Particle Count	Count of spawn particle systems.	✖	✖	✔
Asset ID (SPSC)	Spawn Particle Count	Spawn Particle List	List of spawn particle systems used by this character.	✖	✖	✔

Animation AABB

Type	Name	Notes
string	Animation Name
AABox	Animation Bounding Box

Indexed Animation AABB

Similar to Animation AABB, but with animations referenced via ID instead of name.

Type	Name	Notes
u32	Animation ID	Confirm this is character-relative?
AABox	Animation Bounding Box

Effect

Type	Count	Name	Notes
string	1	Effect Name	Name of the effect.
u32	1	Effect Component Count	Count of effect components
Effect Component	Effect Component Count	Effect Components	Array of effect components used by this effect.

Effect Component

Type	Name	Notes
string	Component Name	Name of this effect component.
FourCC	Particle Asset Type	Type of the particle used by this effect.
Asset ID	Particle Asset ID	Particle resource used by this effect.
string	Bone Name	Bone that the component is attached to.
float	Scale	Scale of the component.
u32	Parented Mode	Needs documentation
u32	Flags	Needs documentation

Animation Set

Type	Count	Name	Notes	MP1	MP2
u16	1	Version	Always 4. Note there are format differences between MP1 and MP2 despite them both being version 4.	✔	✔
u32	1	Animation Count	Count of animations contained by the set.	✔	✔
Animation	Animation Count	Animation Array	Array of animations.	✔	✔
u32	1	Transition Count	Count of transitions contained by the set.	✔	✔
Transition	Transition Count	Transition Array	Array of transitions.	✔	✔
Meta-Transition	1	Default Transition		✔	✔
u32	1	Additive Animation Count	Count of additive animations contained by the set.	✔	✔
Additive Animation	Additive Animation Count	Additive Animation Array	Array of additive animations. Although any animation can be used as additive, this array allows for customizing the fade in/out time for each animation.	✔	✔
float	1	Default Additive Fade-In Time	Fade-in time used for additive animations not listed in the above array.	✔	✔
float	1	Default Additive Fade-Out Time	Fade-out time used for additive animations not listed in the above array.	✔	✔
u32	1	Half Transition Count	Count of half transitions contained by the set.	✔	✔
Half Transition	Half Transition Count	Half Transition Array	Array of half transitions.	✔	✔
u32	1	Animation Resource Count	Count of animation assets used by this set.	✔	✖
Animation Resource Pair	Animation Resource Count	Animation Resource List	List of animation assets used by this set.	✔	✖
u32	1	Event Set Count	Count of event sets. Matches the animation count.	✖	✔
Event Set	Event Set Count	Event Set Array	Array of animation events. Each event set maps to the animation at the same index. Note this is basically MP1's EVNT file format, but embedded in ANCS.	✖	✔

Animation

Type	Name	Notes
string	Name	Animation name.
Meta-Animation	Animation	Meta-animation data.

Transition

Type	Name	Notes
u32	Unknown
u32	Animation ID A	The animation being transitioned from.
u32	Animation ID B	The animation being transitioned to.
Meta-Transition	Transition	Meta-transition data.

Additive Animation

Type	Name	Notes
u32	Animation ID
float	Fade-In Time	Fade-in duration.
float	Fade-Out Time	Fade-out duration.

Animation Resource Pair

Type	Name
Asset ID (ANIM)	ANIM ID
Asset ID (EVNT)	EVNT ID