Binary Curve File Format

Introduction

The purpose of the BinaryCurve file format is to store 3D curve geometry in a compact and efficient-to-read form.

Binary Curve files conventionally use the .binarycurve file extension.

File Layout

Conventions

• All offsets are zero-based (the first byte of the file is at offset 0).
• All offsets and lengths are expressed in bytes.
• All multi-byte fields are using the little-endian (Intel) convention.

High-Level Structure

Field Length	Field Type	Description
11	string	File signature. Must be equal to BINARYCURVE (in capitals) for the file to be considered valid.
2	uint16	File format version
variable	composite	Data block (see below)

The format of the Data block depends on the value of the Version field.

Data Block Format Version 1

Field Length	Field Type	Description
1	uint8	Basis: 1 = Linear, 2 = Bézier, 3 = B-spline, 4 = Catmull-Rom
4	uint32	Number of curves
4	uint32	Number of vertices of curve #1
4	float	X coordinate of vertex #1
4	float	Y coordinate of vertex #1
4	float	Z coordinate of vertex #1
4	float	X coordinate of vertex #2
		...
4	float	Curve width at vertex #1
4	float	Curve width at vertex #2
		...
4	float	Curve opacity at vertex #1
4	float	Curve opacity at vertex #2
		...
4	float	Red component of curve color at vertex #1
4	float	Green component of curve color at vertex #1
4	float	Blue component of curve color at vertex #1
4	float	Red component of curve color at vertex #2
		...