MCMD Filespecification

The MCMD File format

.mcmd is a binary file-type that holds the visual data of a model. It also offers a way to identify the author uniquely.

Without further-a-do here is the current file specification:

<File>

fieldtype	fieldlength	description
unsigned long	8 bytes	magic number, must be 0x4d484643204d444cL
unsigned long	8 bytes	UUIDmost, uniquely identifies a model
unsigned long	8 bytes	UUIDleast, different versions of the same model should have the same UUID
<String>	? bytes	Artist's name
unsigned int	4 bytes	(v) file version
<FileV​v>	? bytes	Differs for different file versions

Currently the following File versions are currently in effect: Version 1

<FileV1>

fieldtype	fieldlength	description
unsigned byte	1 byte	(n) number of parts
unsigned byte	1 byte	(m) number of bones
<ModelPart>[​n]	? bytes	array of model parts, tightly packed
<ModelBone>[​m]	? bytes	array of bones, tightly packed
unsigned byte[​m]	m bytes	bone's parents as indices in the above list, 0xFF means no parent must result in a tree-ish structure

<ModelPart>

fieldtype	fieldlength	description
unsigned short	2 bytes	(p) number of points in this part
unsigned short	2 bytes	(f) number of faces (must be triangles) of this part
<String>	? btyes	name of this part
<Material>	? bytes	material on this part
<Point>[​p]	? btyes	array of points, tightly packed
unsigned short[3*​f]	? bytes	render order of the points as indices. Each tripple makes up one face.

<ModelBone>

fieldtype	fieldlength	description
<String>	? bytes	name of the bone
<Quaternion>	16 bytes	rotation of this bone (in its parent's local matrix)
<Vector3>	12 bytes	offset of this bone (in its parent's local matrix)

<Material>

<Point>

fieldtype	fieldlength	description
<Vector3>	12 bytes	coordinates of the point in model space
<Vector3>	12 bytes	normal vector of this point
<Vector2>	8 bytes	texture coordinates of this point
<Bindings>	? btyes	bone/transform bindings of this point

<Quaternion>

fieldtype	fieldlength	description
float	4 bytes	x-value of the quaternion
float	4 bytes	y-value of the quaternion
float	4 bytes	z-value of the quaternion
float	4 bytes	w-value of the quaternion

<Vector3>

fieldtype	fieldlength	description
float	4 bytes	x-value of the vector
float	4 bytes	y-value of the vector
float	4 bytes	z-value of the vector

<Vector2>

fieldtype	fieldlength	description
float	4 bytes	x-value of the vector
float	4 bytes	y-value of the vector

<Bindings>

<Bindings> = <Binding> <Binding> <Binding> <Binding> | <Binding> <Binding> <Binding> "0xFF" | <Binding> <Binding> "0xFF" | <Binding> "0xFF" | "0xFF"

<String>

<String> = <char> <String> | "0x00"

<char> is any valid unicode UTF-8 byte sequence except 0x00.