nuclear@35: Goat3D animation file format
nuclear@19: ----------------------------
nuclear@35: 
nuclear@35: Chunk structure
nuclear@35: ---------------
nuclear@35: Multiple tracks might apply to the same node, to allow for different
nuclear@35: interpolation, extrapolation, and time ranges between position, rotation, and
nuclear@35: scaling tracks.
nuclear@35: 
nuclear@35: ANIM
nuclear@35:  +--ANIM_NAME
nuclear@35:  |   +--<STRING>
nuclear@35:  +--TRACK
nuclear@35:      +--TRACK_NAME
nuclear@35:      |   +--<STRING>
nuclear@35:      +--TRACK_NODE
nuclear@35:      |   +--<STRING>	(name of the scene node using this track)
nuclear@35:      +--TRACK_ATTR
nuclear@35:      |   +--<STRING>	(specify the attribute affected, see NOTE1)
nuclear@35:      +--TRACK_INTERP
nuclear@35:      |   +--<STRING>    ("step", "linear", "cubic")
nuclear@35:      +--TRACK_EXTRAP
nuclear@35:      |   +--<STRING>	("extend", "clamp", "repeat", "pingpong")
nuclear@35:      +--TRACK_KEY
nuclear@35:          +--TRACK_KEY_TIME
nuclear@35:          |   +--<INT>	(time in milliseconds)
nuclear@35:          +--TRACK_KEY_VALUE
nuclear@35:              +--<FLOAT|FLOAT3|FLOAT4>
nuclear@35: 
nuclear@35: NOTE1: The attribute might be any user-defined string, but the following
nuclear@35: standard attribute names are specified:
nuclear@35:  - "position" keys are (x,y,z) vectors
nuclear@35:  - "rotation" keys are (x,y,z,w) quaternions, with w being the real part
nuclear@35:  - "scaling" keys are (x,y,z) scale factors