Super Monkey Ball 1 Animation File Formats

smb1-anims.md

Super Monkey Ball 1 Animation File Formats

This document describes the format of the four files used for character animation in Super Monkey Ball: motlabel.bin, motdat.lz, motskl.bin, and motinfo.lz.

Types used in this document:

Name	Description
u8	1-byte unsigned value
u16	2-byte unsigned value
u32	4-byte unsigned value
ptr	4-byte value that specifies the file position of some additional data. Unless otherwise specified, this is an offset from the beginning of the file.
f32	4-byte IEEE754 floating point value
string	array of characters followed by a zero byte

All multiple byte values are stored in big endian (most significant byte first).

Note: Any .lz files must be decompressed before being used. This document describes the uncompressed layout of these files.

motlabel.bin

Contains total number of animations and their names

Offset	Type	Name	Description
0x00	u32	animCount	total number of animations
0x04	array of ptr to string	animNames	Array of pointers to each animation name. Note: these are offsets from 0x4 in the file, not from the beginning.

motdat.lz

This file contains the actual data for animations. Each joint has an x position, y position, z position, x-axis rotation, y-axis rotation, and z-axis rotation. These values are called "channels", and are interpolated between "keyframes" of the animation. All angle values are expressed in radians. The contents of motdata.lz are an array of the following structure (one for each animation).

Offset	Type	Name	Description
0x00	u16	?	?
0x04	ptr to array of MotDatJoint	jointInfo	joint info (per joint)
0x08	ptr to array of u16	keyFrameCounts	number of key frames (per channel, per joint)
0x0C	ptr to array of u16	times	key frame timestamp (per keyframe, per channel, per joint)
0x10	ptr to array of u8	valueCounts	number of elements (0-3) in values used by the keyframe (per keyframe, per channel, per joint)
0x14	ptr to array of f32	values	channel values used for interpolation

MotDatJoint (4 bytes)

This structure describes the association between those arrays (keyFrameCounts, times, valueCounts, values) and joints

Offset	Type	Name	Description
0x00	u8	jointIdx	Index of the joint that this applies to
0x02	u16	channelFlags	bit flags specifying which channels the joint has
0x02 bit 8			has x position channel
0x02 bit 7			has y position channel
0x02 bit 6			has z position channel
0x02 bit 5			has x rotation channel
0x02 bit 4			has y rotation channel
0x02 bit 3			has z rotation channel
0x02 bit 2			has unused channel (skip)
0x02 bit 1			has unused channel (skip)
0x02 bit 0			has unused channel (skip)

motskl.bin

Skeletal joint info

Offset	Type	Name	Description
0x00	ptr to array of Skeleton	skeletons
0x04	u32	skeletonCount	number of entries in skeletons
0x08	ptr	?	?
0x0C	u32	?	?

Skeleton (0x18 bytes)

Offset	Type	Name	Description
0x00	ptr	?	?
0x04	ptr to array of ChildJointList	childLists	describes hierarchy of each joint
0x08	ptr to array of MotRotation	rotations	?
0x0C	ptr	?	?
0x10	ptr	?	?
0x14	ptr to string	name	name of skeleton

ChildJointList (8 bytes)

For each joint, an instance of the following structure describes which joints (children) are attached to it.

Offset	Type	Name	Description
0x00	u32	count	number of children (length of array below)
0x04	ptr to array of u8	children	joint indexes of children

MotRotation (0xC bytes)

Offset	Type	Name	Description
0x00	f32	rotX	rotation around x axis
0x04	f32	rotY	rotation around y axis
0x08	f32	rotZ	rotation around z axis

Vec (0xC bytes)

Offset	Type	Name	Description
0x00	f32	x	x component
0x04	f32	y	y component
0x08	f32	z	z component

motinfo.lz

This file associates models and skeletons with each character. This file is an array of the following structure, one entry per character (AiAi, MeeMee, Baby, GonGon). There are 32 entries, but only the first four seem to be relevant.

Offset	Type	Name	Description
0x00	string	skelName	Name of model within the GMA associated with character
0x18	string	modelName	Name of skeleton associated with character
0x30	array of ptr	?	?
0x70	array of u32	?	?
0xB0	ptr	?	?