Particle instances (.particlebin)

Ambient effects (falling leaves and cherry blossom, bird flocks, koi, fireflies, mist, kites, streamers, light shafts) are placed as particle instances: an effect name, a place, a size and a few strings that gate the instance. A track’s are in Ribbon_00\ParticleInstances.particlebin; each route has its own in Stripped\gs\<track>\routedefinitions\route<id>_<track>.particlebin, beside its sound scape. The install holds 170 such files: the Tokyo track’s, the home space’s and 168 route definitions. Proven

Container

A .particlebin is a Grub bundle with one blob, tag PCLB, no metadata records. Proven The blob is version 7.0 in 169 files and 6.0 in the home space’s, which holds no instance; the layout of a version 6.0 file that has instances is unknown. Observed The blob’s data is a memory image: every offset in it is measured from the start of the data. Proven

.particlebin blob datavariableFH6100% known

Little-endian. The 16-byte header, then the instances, then the strings to the end of the data.

ProvenObservedSourcedInferredUnknownNot described

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

0x0

eightu32 = 8

instance countu32

sixteenu32 = 16

first instanceu32

0x10

instancesinstance[]

next

stringscstring[]

Offset	Size	Type	Field	Confidence	Notes
0x0	4	u32 = 8	eight	Proven	all 170 files
0x4	4	u32	instance count	Proven	0 in 92 files, 1 to 87 in 77 route definitions (508 in all), 3,959 in the track's
0x8	4	u32 = 16	sixteen	Proven	the offset of the first instance
0xC	4	u32	first instance	Proven	16, or 0xFFFFFFFF when the count is 0
0x10	129 n	instance[]	instances	Proven
next	variable	cstring[]	strings	Proven	printable ASCII, each zero-terminated; each is named by some instance; empty when the count is 0

particle instance129 bytesFH687% known

Little-endian, unaligned (the byte at 120 shifts what follows). R is the offset of the instance in the blob data. A string field is the offset of the first byte of a string of the strings section; a link is the offset of another slot.

ProvenObservedSourcedInferredUnknownNot described

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

0x0

nameu32

linku32 = R + 8

effectu32

linku32 = R + 112

0x10

constantsu32[4] = 1, 0, 0, 0

0x20

onef32 = 1

positionf32[3]

0x30

rotationf32[4]

0x40

extentf32[3]

nullu32 = 0xFFFFFFFF

0x50

distancef32

zerou32 = 0

nullu32 = 0xFFFFFFFF

linku32 = R + 96

0x60

nullu32 = 0xFFFFFFFF

nextu32

tagu32

linku32 = R + 121

0x70

routeu32

linku32 = R + 104

flagu8

groupu32

linku32 = R + 88

0x80

… link

Offset	Size	Type	Field	Confidence	Notes
0x0	4	u32	name	Proven	string; 986 distinct in the track's file, like falling_leaves_customizable_Instance12
0x4	4	u32 = R + 8	link	Proven
0x8	4	u32	effect	Proven	string; 50 distinct in the track's file, like falling_leaves_customizable
0xC	4	u32 = R + 112	link	Proven
0x10	16	u32[4] = 1, 0, 0, 0	constants	Proven
0x20	4	f32 = 1	one	Proven
0x24	12	f32[3]	position	Observed	world frame; x −17,103 to 6,743, y 93 to 856, z −9,899 to 8,500 in the track's file
0x30	16	f32[4]	rotation	Observed	a unit quaternion x, y, z, w (length within 1.4e-7 of 1 on all 3,959 of the track's file)
0x40	12	f32[3]	extent	Unknown	whole metres up to float rounding: 2, 8, 2 for 681 instances, 5, 9, 4 for about 600
0x4C	4	u32 = 0xFFFFFFFF	null	Proven
0x50	4	f32	distance	Unknown	0 for 86 instances, otherwise 50 to 6,000; 65 for 1,914 of the track's
0x54	4	u32 = 0	zero	Proven
0x58	4	u32 = 0xFFFFFFFF	null	Proven
0x5C	4	u32 = R + 96	link	Proven
0x60	4	u32 = 0xFFFFFFFF	null	Proven
0x64	4	u32	next	Proven	R + 129, or 0xFFFFFFFF on the last instance
0x68	4	u32	tag	Observed	string; empty for 3,956 of the track's file, [TIME_ATTACK_DRIFT_CIRCUIT_HORIZON] for one, 0 for two
0x6C	4	u32 = R + 121	link	Proven
0x70	4	u32	route	Observed	string in the form of a .pgeo header's route string: empty, 0, ~1281, ~351;~8008, ...
0x74	4	u32 = R + 104	link	Proven
0x78	1	u8	flag	Unknown	0 or 1; 1 for 248 of the track's
0x79	4	u32	group	Observed	string; empty for 478 of the track's, otherwise 25 names such as leaves_ginkgo_falling, seagulls_audio, koi_carps
0x7D	4	u32 = R + 88	link	Proven

The links make one singly linked chain through an instance’s seven slots (the five string fields and the two null slots): 0, 8, 112, 104, 121, 88, 96, then the next instance’s 0. Proven Every one of the 4,467 instances holds the values above. Proven

What is known about the fields

• The track’s file names 986 instances, 50 effects and 26 groups; the commonest effects are falling_leaves_customizable (1,911 instances), cherry_blossom_falling_customizable (960), wild_birds_flock_customizable (237), wild_koicarp_customizable (168) and Light_Skyscrapper (134). Observed
• The route string uses the same grammar as the route of a .pgeo header (~ before an id, ids joined by ;); that it gates the instance the same way is not established. Unknown
• The meaning of extent, distance, the byte at 120 and the group string is not established; distance takes the values of a draw distance (50 m to 6 km) but nothing was run to show it. Unknown

How does the game use a particle instance?

The strings suggest a gating by route and gameplay tag, and an audio group; none of it was tested against the running game.