Input

This section describes input related scripts and logic used in OctoXR

Configuration

Input in OctoXR is handled via several main scripts described in further sections. It is mostly abstracted to a certain degree in order to easily add support for additional platforms. It is mainly centered around hand tracking input, but controller support could be added with relative ease as well.

OctoXR uses a single configuration for the representation of a user hand and hand parts. Many scripts and especially input related ones often expose collections of hand bones or other types of objects that always contain a fixed number of elements that can be indexed by hand bone identities. Identities of the hand bones are listed in code via HandBoneId enumeration. Hand bones used by OctoXR as well as their identities and relations are listed in the following table.

Hand part / bone	HandBoneId	Parent HandBoneId	Index / ID Number
Wrist bone	Wrist	-	0
Palm center	Palm	Wrist	1
Thumb finger metacarpal bone	ThumbMetacarpal	Wrist	2
Thumb finger proximal phalanx	ThumbProximal	ThumbMetacarpal	3
Thumb finger distal phalanx	ThumbDistal	ThumbProximal	4
Thumb finger tip	ThumbTip	ThumbDistal	5
Index finger metacarpal bone	IndexMetacarpal	Wrist	6
Index finger proximal phalanx	IndexProximal	IndexMetacarpal	7
Index finger intermediate phalanx	IndexIntermediate	IndexProximal	8
Index finger distal phalanx	IndexDistal	IndexIntermediate	9
Index finger tip	IndexTip	IndexDistal	10
Middle finger metacarpal bone	MiddleMetacarpal	Wrist	11
Middle finger proximal phalanx	MiddleProximal	MiddleMetacarpal	12
Middle finger intermediate phalanx	MiddleIntermediate	MiddleProximal	13
Middle finger distal phalanx	MiddleDistal	MiddleIntermediat	14
Middle finger tip	MiddleTip	MiddleDistal	15
Ring finger metacarpal bone	RingMetacarpal	Wrist	16
Ring finger proximal phalanx	RingProximal	RingMetacarpal	17
Ring finger intermediate phalanx	RingIntermediate	RingProximal	18
Ring finger distal phalanx	RingDistal	RingIntermediate	19
Ring finger tip	RingTip	RingDistal	20
Little finger metacarpal bone	LittleMetacarpal	Wrist	21
Little finger proximal phalanx	LittleProximal	LittleMetacarpal	22
Little finger intermediate phalanx	LittleIntermediate	LittleProximal	23
Little finger distal phalanx	LittleDistal	LittleIntermediate	24
Little finger tip	LittleTip	LittleDistal	25

Certain bones in the previous table, such as finger tips and hand palm don't correspond to any real bone in human hand. These bones are mostly auxiliary bones used throughout OctoXR in order to e.g. determine the length of the top-most phalanx of a particular finger or to quickly determine where the user points with his/her particular finger etc. These bones are considered as non-rotating bones. All the rest, with the exception of non-thumb finger metacarpal bones, are considered as rotating, i.e they rotate relative to the bones they are attached to (their parent bones) or, in case of Wrist bone, they rotate relative to the absolute space used as the common frame of reference for every object in the scene - world space.

In addition to hand bones there are several places where you can access certain members indexed by hand fingers. Fingers are listed in HandFinger enumeration and they are, in order with their indices: Thumb (0), Index (1), Middle (2), Ring (3), Little (4).