Helper Joints: Advanced Deformations on RunTime Characters - PowerPoint PPT Presentation

About This Presentation
Title:

Helper Joints: Advanced Deformations on RunTime Characters

Description:

Title: PowerPoint Presentation Author: CMP WS Last modified by: Nancy Yu Created Date: 4/21/2004 4:23:17 PM Document presentation format: On-screen Show – PowerPoint PPT presentation

Number of Views:857
Avg rating:3.0/5.0
Slides: 116
Provided by: CMP5
Category:

less

Transcript and Presenter's Notes

Title: Helper Joints: Advanced Deformations on RunTime Characters


1
Helper JointsAdvanced Deformations on RunTime
Characters
  • Jason Parks
  • Character Technical Director
  • Sony Computer Entertainment America

2
Contacts, Reference, Credits
  • Email
  • jason_at_jason-parks.com
  • jason_parks_at_playstation.sony.com
  • Webpage (Helper Joints-GDC 2005)
  • http//www.jason-parks.com/HelperJoints
  • PAN Arts AVIs by Warwick Mellow
  • Human Model by Sven Jenson via Miller/Thuriots
    MasterClass 2003 (Character Creation Toolkit)
  • BodyBlend render by Zach Gray
  • Wrinkle RD by Tyler Crook (SCEA)

3
Intended Audience
  • Advanced Requires experience and familiarity
    with subject.
  • Maya Technical Artists who Bind Characters for
    RunTime or Offline usage
  • Paint weights (Artisan and Component Editor)
  • Apply deformers
  • Use Set Driven Keys
  • Write Expressions
  • Use Utility Nodes

4
Topics
  • What are Helper Joints?
  • Definition
  • Why use Helper Joints?
  • New uses for Extra Joints
  • Smooth binding sucks Where to use Helper Joints
  • How to use Helper Joints?
  • Our Goals, Disclaimer, Fusiforms
  • Research The Basic Building Blocks
  • RunTime Rigs
  • SetDrivenKeys
  • Expressions
  • Constraints
  • Non-RunTime Rigs
  • Baking Out
  • Spline IK
  • Jiggle Deformer
  • Automating Production
  • Scripting
  • Workflow

5
Stop Talking, No more text, show some Moving
Pictures!
6
Helper Joints Defined
  • Helper Joints are secondary joints offset from
    the standard hierarchy which will translate,
    rotate, or scale to achieve a hand sculpted
    affect on an area of vertices.
  • They can be within the primary hierarchy
    (parented, grouped, rigged), or outside of the
    primary hierarchy (point or parentConstrained)
  • They can be controlled by SetDrivenKeys,
    Expressions, Simple Rigs (constraint system), or
    Super Advanced Rigs (really any simulation you
    can think of) that are baked-out.

7
Why use any Extra Joints?
Unlike characters rigged, bound, and rendered in
Maya or any other high-end 3D package, your
characters at run-time need to follow a very
specific rule set depending on your Game Engine.
Because all run-time engines already support
joints, it is a tool we can exploit and push to
its limits.
  • Traditional usage of Extra Joints to animate
    Props and Accessories
  • Extra Helper Joints to fix Smooth binding
  • Extra Helper Joints to create the next level in
    realism

8
Traditional Extra Joints
  • Traditional usage of Extra Joints for Props and
    Accessories
  • Props, Rope
  • Hair, Ponytails
  • Capes, Necklaces, Clothing
  • Fat

9
New Ideas for Extra Joints
  • Extra Helper Joints to create the next level in
    realism
  • Skin sliding
  • Wrinkles
  • Fat/Muscle/Flesh Jiggle
  • Muscle bulging

10
Fix Smooth binding
  • Extra Helper Joints to make skin transform
    properly
  • Volume maintenance
  • Crease fixing
  • Complex Areas
  • Multiple joints affecting a single vert

11
Smooth Binding Limited
  • Vertex deforms by a weighted combination of
    Linear Translations around a joint rotating

12
Smooth Binding Shoulder
13
Smooth Binding Problem Areas
  • Elbow and Knee
  • Interpenetration on the inside of the crease
  • Loss of volume on the outside of the crease (i.e.
    the elbow tip or knee cap do not become
    pointy when the elbow or knee bends)
  • Wrist/Forearm
  • Loss of volume when the forearm/wrist is twisted
    too much down the length of the arm. (i.e. -
    Candy-wrapper affect)
  • Upper Thigh/Gluteus
  • Interpenetration at the bottom of the butt cheek
    when leg goes too far back
  • Shoulders
  • Interpenetration in armpit
  • Interpenetration at the neck/shoulder junction
    area (trapezius)
  • Lack of representation of scapula movements

14
Our Goals The Ideal
  • What are we really trying to get?
  • Reference with Motion
  • Books
  • Anatomy of Movement by Blandine C. Germain
  • Internet
  • PAN Arts by Warwick Mellow
  • Software
  • Absolute Character Tools for 3DSMAX

15
Our Goals
  • PAN Research
  • Pectorals
  • Shoulders

16
Our Goals
  • PAN Research
  • Clavicle
  • Forearm

17
Our Goals
  • Muscles Independent Research

18
Our Goals
  • Muscles - Absolute Character Tools

19
Disclaimer RunTime Rig Support
  • Individual Developer code will dictate what will
    be evaluated in Real-Time and what type of
    relation you can specify between your primary
    skeletons animation and your Helper Joints
    transformation.
  • Hopefully you can get 1 or more of these RunTime
    Rigging methods supported
  • SetDrivenKeys
  • Expressions
  • Constraints

20
Disclaimer RunTime Rig Support
  • NO
  • Source Code provided for engine side.
  • YES
  • Techniques for art-side production of rigs (in
    Maya)
  • Applicable to all games on all consoles

21
How To Get There
  • Muscles are the drivers in reality so lets create
    Helper Joints that mimic the way muscles work.
  • Simple FusiForm muscles are easy to mimic in Maya
    so lets create those and bind them to our skin

22
Research FusiForm Muscle
  • FusiForm muscle Quick Definition
  • Tapering at each end spindle-shaped.

23
Research The Building Blocks
  • Lets pick the Biceps as our test case to create
    a muscle and mimic its action with a Helper Joint
    being driven by SetDrivenKeys
  • Rotating
  • Scaling
  • Translating
  • The research explores the underlying mechanisms
    of the rigs
  • The failed attempts still illustrate how rigs
    can be put together

24
Research The Building Blocks
  • UNDERSTANDING HOW THE RIGS WORK
  • IS MORE VALUABLE
  • THEN MY SUGGESTED SOLUTIONS

25
Research Biceps (NURBs)
  • Muscle as Influence Object - NURBs

26
Research Biceps (Polys)
  • Muscle as Influence Object - Polygons

27
Research Biceps (Short)
  • SetDrivenKey w/ Single Driver Axis
  • Rotating
  • Short

28
Research Biceps (Long)
  • SetDrivenKey w/ Single Driver Axis
  • Rotating
  • Long

29
Research Biceps (Scale)
  • SetDrivenKey w/ Single Driver Axis
  • Scaling

30
Research Biceps (Translate)
  • SetDrivenKey w/ Single Driver Axis
  • Translate

31
Research Upper Arm (Translate)
  • Single Driver Axis
  • Translate
  • Works pretty good for Single driving axis!
  • Warning Not anatomically correct!

32
Research Biceps (RollBone)
  • SetDrivenKey w/ Single Driver Axis
  • Translate
  • Add Roll
  • BREAKS!

33
Research Biceps (RollBone)
  • SetDrivenKey w/ Two Driver Axis
  • Translate
  • Add Roll
  • w/ Extra Keys compensating for roll
  • Only fixes in when arm is straight out
  • When arm is bent it still BREAKS!

34
Research Biceps (RollBone)
  • Add parent joint w/ another set of driven keys
    for roll
  • Rotation of Helpers parent joint is percentage
    of primary hierarchies rotation

35
Research Shoulder (Multiple Drivers)
  • SetDrivenKey w/ Single Driver Axis from Two bones
  • Translate
  • Combination is difficult

36
Research Shoulders (Multiple Drivers)
  • SetDrivenKey w/ Two Driver Axis from Two bones
  • Translate
  • 2 Driving bones BREAKS!(kinda)
  • 2 Driving axis BREAKS!BAD!

37
RunTime Rigs SetDrivenKeys
  • Summation
  • SetDrivenKeys are fast, easy to use and work
    great for simple Helper Joints
  • 1 driveR joint and 1 driveR axis per driveN
    Helper Joint
  • Nest hierarchies of driveN Helper Joints if you
    have more than 1 driveR joint or axis

38
RunTime Rigs SDKs for Volume Preservation
  • Forearm Helper Joint w/ SDKs for Scale and
    rotation

39
RunTime Rigs SDKs for Wrinkles
  • Scaling of Helper Joints (RD by Tyler Crook _at_
    SCEA)

40
RunTime Rigs SDKs for Wrinkles
  • Joints are scaling on 2-axis (bulging), no
    scaling on length-wise axis
  • No translation or rotation

41
RunTime Rigs SDKs for Wrinkles
  • Weighting is very tedious

42
RunTime Rigs SDKs for Wrinkles
  • For shirt it takes many more joints because of 3
    D.O.F. and larger surface.
  • 6 joints to do it right

43
RunTime Rigs SDKs for Wrinkles
  • Different joints scale for each direction in each
    D.O.F.
  • Weighting is time consuming

44
RunTime Rigs SDKs for Wrinkles
  • Incorporation
  • Could theoretically add a scaling joint as a
    child of the helper joints
  • Then just weight individual vertices to these
    scaling joints to cause wrinkling
  • Or just make separate scaling wrinkle joints
    wherever needed

45
RunTime Rigs
  • Done with SDKs
  • Start Expressions

46
RunTime Rigs Expressions (SimpleElbow)
  • Simple Helper Joints which only need a
    Translation Expression
  • Based on 1 axis from driving bone
  • dj_helper.ty (base.ty (maxOffset (elbow.rz
    /maxAngle)))

47
RunTime Rigs - Expressions (ComplexBiceps)
  • Complex Helper Joints which need Translation
    Rotation Expression
  • Translation Use another expression to translate
    dj_bicep joint (parented to Bicep_Helper) for
    bulge based on elbow rotation.
  • Expression 2 Describes bulge from rotation of
    elbows Z-axis
  • dj_bicep.ty (base.ty (maxOffset (elbow.rz
    /maxAngle)))
  • base.ty 5, maxOffset 1.8, maxAngle 110
  • Rotation Joint needs to be parented to both
    shoulder and bicep-roll joints. Use Expression to
    take percentage.
  • Expression 1 Describes rotation of parent joint
    around bicep-roll joint. (60 from shoulder, 40
    from bicep-roll)
  • Bicep_Helper.rx ((.4 bicep.rx) (.6
    shoulder.rx))

48
RunTime Rigs - Expressions (ComplexBiceps)
  • Rotation Bicep_Helper.rx ((.4 bicep.rx)
    (.6 shoulder.rx))
  • Translation dj_bicep.ty (base.ty (maxOffset
    (elbow.rz /maxAngle)))
  • base.ty 5, maxOffset 1.8, maxAngle 110

49
RunTime Rigs Expressions Constraints
(ComplexBiceps)
  • Complex Helper Joints which need Scale Rotation
    Expressions but looking at Distance
  • Requires 6 extra parent helpers (can be joints or
    nulls)
  • Component 1 Scale (Bulge)
  • Handled by expression based on distance of
    shock-absorber
  • bicepHelper.sz (scaleFactor(1/(boneLength)))
    boneLength sqrt ((foreArmOffset.tx
    bicepOffset.tx)² (foreArmOffset.ty
    bicepOffset.ty)² (foreArmOffset.tz
    bicepOffset.tz)²)
  • Component 2 Rotate
  • Handled by expression base on of angle of
    bicep_roll
  • Bicep_Helper.rx ((.4 bicep.rx) (.6
    shoulder.rx))
  • Requires 2 pointConstraints

50
RunTime Rigs Expressions Constraints
(ComplexBiceps)
  • Scale Expression based on distance

51
RunTime Rigs - Expressions
  • Summation
  • Very difficult to describe a motion of a Complex
    Helper Joint based on 2 or more axis from driving
    joint. Even MORE difficult when there are
    multiple bones acting as drivers.

52
RunTime Rigs
  • Done with Expressions
  • Start with Constraints

53
RunTime Rigs - Constraints
  • pointConstraint
  • Good for position only
  • orientConstraint
  • Good for orientation only
  • parentConstraint
  • Good for both position and orientation
  • aimConstraint
  • Robust and elegant
  • vertexConstraint
  • Allows the use of muscles

54
RunTime Rigs - Constraints
  • AIMCONSTRAINT
  • IS
  • DA BOMB!

55
RunTime Rigs Constraints (ComplexBiceps)
  • aimConstraint pointing at forearm
  • Arc problem
  • Handles rotation of bicep roll on extension but
    not flexion

56
RunTime Rigs Constraints (ComplexBiceps)
  • aimConstraint flexion problem
  • Handles rotation of bicep roll on extension but
    not flexion

57
RunTime Rigs Constraints (ComplexBiceps)
  • aimConstraint flexion problem handled on XZ plane
    w/ expression for Bulge
  • Bicep_HelpersParent.scale (baseScale
    (maxOffset (elbow.rz /maxAngle)))
  • i.e. - baseScale 1, maxOffset .3, maxAngle
    110

58
RunTime Rigs Constraints (ComplexBiceps)
  • aimConstraint still broken on Y plane during
    flexion

59
RunTime Rigs Constraints (ComplexPectoralis)
  • Requires 2 extra parent helpers (can be joints or
    nulls)
  • Requires 1 aimConstraint

60
RunTime Rigs Constraints (ComplexArmPit)
  • Requires 2 extra parent helpers (can be joints or
    nulls)
  • Requires 1 aimConstraint

61
RunTime Rigs Constraints (ComplexPectoralis
Armpit)
  • Requires 3 extra parent helpers (can be joints or
    nulls)
  • Requires 2 aimConstraints

62
RunTime Rigs Constraints (SimpleNeck)
  • Look at normal smooth bind

63
RunTime Rigs Constraints (SimpleNeck)
  • NURBs muscle as Influence Object

64
RunTime Rigs Constraints (SimpleNeck)
  • Requires 1 helper joint and 1 target null for
    aiming
  • Requires 1 aimConstraint

65
RunTime Rigs Constraints (SimpleNeck)
  • Comparison

66
RunTime Rigs Constraints (SimpleNeck - Back)
  • Requires 1 helper joint and 1 target null for
    aiming
  • Requires 1 aimConstraint

67
RunTime Rigs Constraints (SimpleNeck - All)
  • Requires 4 helper joints w/ 4 extra target nulls
  • Requires 4 aimConstraints

68
RunTime Rigs Constraints (SuperComplex
Scapula)
  • Look at normal smooth bind

69
RunTime Rigs Constraints (SuperComplex
Scapula)
  • What is scapula really doing?

70
RunTime Rigs Constraints (SuperComplex
Scapula)
  • Comparison

With Rig
Normal Binding
71
RunTime Rigs Constraints (SuperComplex
Scapula)
  • Shrugging

72
RunTime Rigs Constraints (Exp./SDK)
(SuperComplex Scapula)
  • Requires 2 helper joints and 2 target nulls for
    aiming
  • Requires 2 aimConstraints 1 pointConstraint
  • Requires expression w/ if statement
  • If (lShoulder.rotateY gt0)
  • l_scapulaConst.rotateX ( scaleFactor
    (lShoulder.rotateY/maxAngle))
  • Else
  • l_scapulaConst.rotateX 0
  • Ex scaleFactor 30 degrees and maxAngle 90
    degrees.
  • OR SetDrivenKey

73
RunTime Rigs Constraints (Exp./SDK)
(SuperComplex Scapula)
  • Explanation of (SDK or If statement in
    expression)

74
RunTime Rigs Constraints (Exp./SDK)
(SuperComplex Scapula)
  • Pros Full Range Looks Great
  • Cons Complex and Weighting is Hard!

75
RunTime Rigs Expression/SDK (Complex
ArmPitBack)
  • Normal armpit crease

76
RunTime Rigs Expression/SDK (Complex
ArmPitBack)
  • New Helper Joint added

77
RunTime Rigs Expression/SDK (Complex
ArmPitBack)
  • Translation of Helper Joint tip driven by
    expression or SetDrivenKey from shoulder rotation
  • Requires 1 extra parent Helper Joint w/
    percentage rotation of shoulder driven by Rotate
    expression or SetDrivenKey

78
RunTime Rigs Expression/SDK (Complex
ArmPitBack)
  • armPitParent Joint rotating 60 of shoulder joint

79
RunTime Rigs Exp./SDK (Complex ArmPitBack)
  • armPitTip joint translating down its local X Y
    as a function of shoulder rotation

80
RunTime Rigs Exp./SDK (Complex ArmPitBack)
  • Requires 1 simple expression for parent Joints
    rotation
  • HelperParent.rotateY (offset angle (( arm
    rotate) lShoulder.rotateY)))
  • Ex - dj_armPitBackParent.rotateY (-35 (.6
    lShoulder.rotateY))
  • Requires 1 expression for translation of tip w/
    if statement
  • If (lShoulder.rotateY lt0)
  • HelperTip.translateX (base.tX
    (scaleFactorX(lShoulder.rY/maxAngle)))
  • HelperTip.translateY (base.tY
    (scaleFactorY(lShoulder.rY/maxAngle)))
  • Else
  • HelperTip.translateX baseX
  • HelperTip.translateY baseY
  • Ex scaleFactorX 2 units, scaleFactorY -4
    units and maxAngle 65 degrees.

81
RunTime Rigs Exp./SDK (Complex ArmPitBack)
  • Weighting is powerful and tricky. Some vertices
    now have 5 different weights.

82
RunTime Rigs Scaling Entire Rig
  • What if character needs to be scaled? (i.e.-
    player defined proportions)
  • A simple Group node above the rig mechanism in
    Mayas hierarchy will scale easily
  • The Trick is figuring out how much to scale. This
    is dependent on what space the helper joint
    deforms, and how that space has been scaled.

83
RunTime Rigs
  • Done with Constraints
  • Start with Muscles

84
RunTime Rigs - Muscles
  • Muscles at RunTime allows you to constrain Helper
    Joints to the muscle surface and get the effect
    of the muscle
  • Requires some sort of geometryConstraint

85
RunTime Rigs Constraints Bind Blendshape
(MusclesBiceps)
  • Deformer Object is low-count poly muscle rigid
    (or smooth) bound to two joints to handle
    twisting of bicep
  • Requires a blendShape on deformer object to
    handle bulge.
  • Note blendShape is not required on main
    skinning surface.
  • Complex Helper Joint is VertexConstrained to
    vertex on Deformer Object

86
RunTime Rigs Constraints Bind Blendshape
(MusclesBiceps)
  • VertexConstrained

87
RunTime Rigs Constraints Bind SDK
(MusclesBiceps)
  • Poly Muscle (Simplest Form)
  • 1 triangle Rigid (or Smooth) Bound
  • Handles rotation of bicep
  • SDK (or simple expression 1 driving bone/axis, 1
    driven translating axis) driving single vertex
    for bulge
  • Complex Helper joint VertexConstrained to
    single vert
  • Finally skinning layer

88
RunTime Rigs Constraints Bind SDK
(MusclesBiceps)
  • 1 Poly (Simplest Form)
  • VertexConstraint

89
RunTime Rigs Constraints Bind
(MusclesPectoralis)
  • Deformer Object is low-count poly muscle rigid
    (or smooth) bound to three joints to handle
    complex Pectorals motion
  • Requires MuscleDriver parent joints to be offset
    from main skeletal joints
  • MuscleDriver child joints are pointConstrained
    to parent joints to avoid rotation of parent
    joints
  • Complex Helper Joint is VertexConstrained to
    vert on Deformer Object

90
RunTime Rigs Constraints Bind
(MusclesPectoralis)
  • PointConstraints VertexConstraints

91
RunTime Rigs to Non-RunTime
92
Non-RunTime Rigs
  • Helper Joints Definition
  • They can be controlled by SetDrivenKeys,
    Expressions, Simple Rigs (constraint system), or
    Super Advanced Rigs (really any simulation you
    can think of) that are baked-out.

93
Non-RunTime Rigs - Baked Out
  • BakeOut examples
  • Bicep
  • Complex Helper Joints constrained to nurbsMuscle
    influence object, baked out, 1 key per frame,
    scene cleaned.

94
Non-RunTime Rigs - Baked Out
  • BakeOut examples
  • Pectorals
  • Complex Helper Joints constrained to nurbsMuscle
    influence object, baked out, 1 key per frame,
    scene cleaned.

95
Non-RunTime Rigs - Baked Out
  • BakeOut examples
  • Pectorals
  • Lots!

96
Non-RunTime Rigs - SplineIK
  • Great Skin-sliding effect

97
Non-RunTime Rigs - Jiggle
  • Basic Jiggle is fairly easy to create in Maya,
    either with a
  • Simple Expression
  • frameCache node
  • Could be turned into RunTime if your code
    supported it

98
Non-RunTime Rigs - Jiggle
  • Create a 1 (or more) frame lag in global space
    for a joint
  • BaseJoint Goal
  • Blue joint parented to spine
  • EndJoint Weighted
  • Yellow joint lagging behind Blue joint by 1 frame

99
Non-RunTime Rigs - Jiggle
  • Expression
  • int frame frame // get the current frame
  • float tx_0 BellyJiggleBase.translateX
  • float tx_1
  • // reset the attributes on start frame
  • if (frame 1) // start frame
  • tx_1 tx_0
  • BellyJiggleEnd.translateX tx_0
  • else
  • BellyJiggleEnd.translateX tx_1
  • tx_1 tx_0
  • Repeat for Y Z axis

100
Non-RunTime Rigs - Jiggle
  • frameCache Node

101
Non-RunTime Rigs - Jiggle
frameCache Expression
102
Non-RunTime Rigs - Jiggle
  • Incorporation
  • Could theoretically add a jiggle joint as a child
    of the helper joints
  • Then just weight individual vertices to these
    jiggle joints to cause jiggling
  • Or just make separate jiggle joints and their
    base joint wherever needed
  • Where are they needed?

103
Non-RunTime Rigs to Automation
104
Automating Production
  • Scripts
  • Workflow
  • Offline Muscle Systems
  • Procedurally generated Helper Joints

105
Automating Production
  • Scripts Tools youll need
  • Script to auto-build entire Helper Joint System
    on your character
  • Selectable body parts
  • Scripts to automate editing of Rigs,
    SetDrivenKeys, Expressions for the artists
  • Scripts to do lots of mirroring
  • Helper Joint Rigs
  • Weighting
  • Set Driven Keys
  • Export and Import Set Driven Keys
  • Hint look at the animCurves and add custom attrs
    for connections to them upon export
  • Demo

106
Automating Production
  • Workflow
  • Duplicate your primary skeleton and skin
  • Apply your muscle system to this duplicate
    character
  • Constrain duplicate skeleton to primary skeleton
  • Hide duplicated skeleton, muscles, rigs.
    Template duplicated skin.

107
Automating Production
  • Workflow

108
The Ultimate Reference
  • Muscle Systems

109
The Ultimate Reference
  • Muscle Systems

110
The Ultimate Reference
  • Muscle Systems
  • Auto imports muscle system
  • Scaling to your skeleton
  • AutoFits muscles to duplicated skin
  • AutoSkins muscles to duped skin

111
The Ultimate Reference
  • Once you have the Ultimate Reference, you now
    have the data to let a programmer put you out of
    a job. All (s)he needs to figure out is
  • How many joints?
  • Where to place them?
  • How do they need to transform?
  • What does their weighting need to be?

112
Mohr/Gleicher Method
  • Siggraph 2003 Building Efficient, Accurate
    Character Skins from Example
  • White Paper on auto-computing placement,
    animation, and weighting of Helper Joints.

113
Conclusion
  • Weve covered just a few examples of how to use
    SetDrivenKeys, Constraints, and Expressions.
  • My solutions are just first shot attempts. With
    refinement, you can come up with much better
    solutions.
  • With these simple tools you can use them in many
    combinations to achieve nearly any effect you
    need.
  • Of course everything is RunTime code dependent.
    As Character T.D.s we need to fight for
  • SetDrivenKeys
  • Constraints
  • Point, orient, !!AIM!!, parent, geometry
  • Expressions
  • Spline IK
  • frameCache (jiggle)
  • Helper Joints are just a temporary solution until
    we can get more advanced deformers at RunTime to
    simulate Muscles
  • Per-vertexDeformer (influence objects)
  • WrapDeformer (lattices)
  • fusiForm deformer
  • . . . Talk more about this next year?

114
Thanks
  • for your time.
  • Please fill out surveys so I can make a better
    one next year.
  • Peace out

115
Contacts, Reference, Credits
  • Email
  • jason_at_jason-parks.com
  • jason_parks_at_playstation.sony.com
  • Webpage (Helper Joints-GDC 2005)
  • http//www.jason-parks.com/HelperJoints
Write a Comment
User Comments (0)
About PowerShow.com