A Maya Spline is a 2D hermite curve first introduced in Metroid Prime 2: Echoes. It's used in various file formats to animate some sort of effect over time. It most commonly shows up in MREA files in script object properties, but it can also appear in other formats.
Format
Structure Metroid Prime 2/3
Type
Count
Name
Notes
u8
1
Pre Infinity Infinity setting for time ranges before the start time of the spline curve.
u8
1
Post Infinity Infinity setting for time ranges after the end time of the spline curve.
u32
1
Knot Count
Number of knots in the spline.
Knot
Knot Count
Knot Array
Array of knots forming the actual spline.
u8
1
Clamp Mode Clamp mode setting.
float
1
Minimum Amplitude
Minimum amplitude used for clamped splines.
float
1
Maximum Amplitude
Maximum amplitude used for clamped splines.
Donkey Kong Country Returns Basically the same data as in Prime 2/3, but shifted around slightly.
Type
Count
Name
Notes
u32
1
Knot Count
Number of knots in the spline.
Knot
Knot Count
Knot Array
Array of knots forming the actual spline.
float
1
Minimum Amplitude
Minimum amplitude used for clamped splines.
float
1
Maximum Amplitude
Maximum amplitude used for clamped splines.
u8
1
Pre Infinity Infinity setting for time ranges before the start time of the spline curve.
u8
1
Post Infinity Infinity setting for time ranges after the end time of the spline curve.
u8
1
Clamp Mode Clamp mode setting.
Knot
Offset
Type
Name
Notes
0x0
float
Time (X)
Time the knot is placed at; also serves as the knot's X position on the spline.
0x4
float
Amplitude (Y)
Amplitude of the knot; also serves as the knot's Y position on the spline.
0x8
u8
Unknown
0x9
u8
Unknown
Infinity Type Enum
This file format is almost completely documented this page .
Clamp Mode Enum
ID
Mode
0
Unclamped
1
Clamped between min/max
2
Unknown
