The Visia Avatar

The supplied avatar provided by the ViSiCAST Control v2.0 is Visia, shown below.

An Overview of Bones within MaskVR

The avatar's mesh is wrapped over a 'skeleton' which is composed of 78 'bones'. These bones act as control values for the mesh deformation algorithm. They do not necessarily represent anatomical bones (although in the case of the main body and hands they do). Each bone is represented as 13 floating point values, and can be represented in either two forms: Global or Local. A globalised bone has its values defined in terms of the global co-ordinate system, whilst a localised bone is defined in the co-ordinate system of a parent. Bones are always aligned along their x-axis. The following table describes each value required to describe a bone.

Description		Global Mode	Local Mode
Length		Length of the bone in within the global co-ordinate system.	Length of the bone in within the global co-ordinate system.
X Axis	X	Given in the global co-ordinate system.	Given in the parent's co-ordinate system.
	Y
	Z
Y Axis	X	Given in the global co-ordinate system.	Given in the parent's co-ordinate system.
	Y
	Z
Z Axis	X	Given in the global co-ordinate system.	Given in the parent's co-ordinate system.
	Y
	Z
Position	X	Defined in the global co-ordinate system scale.	Each unit is defined as the length of the parent bone.
	Y
	Z

Visia's Bones

Visia is composed from 78 bones, which form a hierarchy. The hierarchy is described in the following table.

Index	Name	Parent
0	lower_back	1
1	mid_back	2
2	top_back	-1
3	neck	2
4	head	3
5	left_shoulder	2
6	left_upper_arm	5
7	left_forearm	6
8	left_hand	7
9	right_shoulder	2
10	right_upper_arm	9
11	right_forearm	10
12	right_hand	11
13	left_slap	6
14	right_slap	10
15	neck_slap	2
16	left_upper_corner_lip	4
17	left_upper_lip	4
18	right_upper_lip	4
19	right_upper_corner_lip	4
20	left_lower_corner_lip	4
21	left_lower_lip	4
22	right_lower_lip	4
23	right_lower_corner_lip	4
24	left_brow	4
25	right_brow	4
26	right_jaw	4
27	left_jaw	4
28	chin	4
29	left_cheek	4
30	right_cheek	4
31	necky	3
32	left_eyelid	4
33	right_eyelid	4
34	left_eye	4
35	right_eye	4
36	left_ThumbMagic	8
37	left_ThumbTMJ	36
38	left_ThumbMPJ	37
39	left_ThumbIJ	38
40	left_IndexMCJ	8
41	left_IndexMPJ	40
42	left_IndexPIJ	41
43	left_IndexDIJ	42
44	left_SecondMCJ	8
45	left_SecondMPJ	44
46	left_SecondPIJ	45
47	left_SecondDIJ	46
48	left_ThirdMCJ	8
49	left_ThirdMPJ	48
50	left_ThirdPIJ	49
51	left_ThirdDIJ	50
52	left_PinkyMCJ	56
53	left_PinkyMPJ	52
54	left_PinkyPIJ	53
55	left_PinkyDIJ	54
56	left_PinkyMagic	8
57	right_ThumbMagic	12
58	right_ThumbTMJ	57
59	right_ThumbMPJ	58
60	right_ThumbIJ	59
61	right_IndexMCJ	12
62	right_IndexMPJ	61
63	right_IndexPIJ	62
64	right_IndexDIJ	63
65	right_SecondMCJ	12
66	right_SecondMPJ	65
67	right_SecondPIJ	66
68	right_SecondDIJ	67
69	right_ThirdMCJ	12
70	right_ThirdMPJ	69
71	right_ThirdPIJ	70
72	right_ThirdDIJ	71
73	right_PinkyMCJ	77
74	right_PinkyMPJ	73
75	right_PinkyPIJ	74
76	right_PinkyDIJ	75
77	right_PinkyMagic	12

Bones of the Body

The bones of the body (torso, arms and neck) are show in the following diagram.

There are three so-called, slap bones in the body: left_slap right_slap and neck_slap. These are used in areas were x-axis rotations are common and can cause significant folding effect on the mesh. Each slap bone is oriented in the same x-axis of a counter-part bone (i.e. right_forearm, left_forearm or neck), but with an approximately 90 degrees rotation about the x-axis. The mesh attachment in these areas are specially set up in order to minimise folding during mesh deformation.

Bones of the Face

Bones of the Hands

The following diagram shows the named bones of the left hand. Each bone is represented as a double pyramid. As always the bone lies along its x-axis. This axis, together with a triangle representing the XY plane has been highlighted in white. There are two special bones in the hand called 'Thumb Magic' and 'Pinky Magic'. 'Thumb Magic' is responsible for allowing the rotation of the thumb about the axis formed by the index knuckle and the meta-carpal joint. 'Pinky Magic' allows for the curving of the palm caused by the Pinky Meta Carpal Joint bone, about the axis formed by the third knuckle and the base of the Pinky MCJ.

ã September 2000 Televirtual LTD