Course notes
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Lecture 1: Intro to Animating with Maya Lecture 9: Character Set and Trax Editor
Lecture 2: Keyframing, Graph Editor, Playblast Lecture 10: Rigging a Sack
Lecture 3: Digital Audio Lecture 11: Inverse Kinematics on a Sack
Lecture 4: Audio, Projects, Hierarchy, Principles Lecture 12: Camera Moves and Positions
Lecture 5: Rendering, After Effects Lecture 13: Understanding Single Chain and Rotate IK
Lecture 6: Ball Bounce Lecture 14: Binding the Skin of the Sack
Lecture 7: Path Animation Lecture 15: Principles of Animation
Lecture 8: Forward K and Constraints Lecture 16: Making a Playable DVD
 Lecture 14: Binding the Skin of the Sack
[14]Preparation of the Sack

Make sure you delete history on the Sack

The texture on the sack is wrong - you must fix it

Select the sack
Window - UV Texture Editor
Hit f to fit in the window
We need to get rid of the overlapping UV
Relayout the UV so it fits in the 1 to 1 scale

Polygon menu set
Create UVs - Cylindrical Mapping - Options

Turn off the image - click the face icon

Must get it to fit in the box
You should think about mapping Planar like you did with the Airplane last semester.
[15] Skinning

MAKE sure all curves are set to 0 before starting this next step:
You should Skin before animating but you can paint weights after you animate

Hide IK Handles in the Show window inside the modeling window

You can use the Show menu in the modeling window to hide joints, curves, and polygons

We will need to only see the joints for now:
In the Outliner - Show - Objects - Joints

Hold shift and click the plus in the Outliner to expand all

Selecting the joints:

Ctrl click all the joints but not the end ones (you do not need the toes and hands)
Hold shift key and select the mesh geometry of the sack last (you may need to turn back it on)
If you have clothing or other things attached to the sack, select them too

***Do not select the curves when binding the skin

Skin - Bind Skin - Smooth Skin Options
Bind to: Selected joints
Bind method: Closest in hierarchy
(if you were doing a hand it would select the closest finger and bind it wrong)
Max influence: 1
(one chunk belongs to one area of the mesh)

After Bind: Uncheck Maintain Max Influences
This allows the joint to effect the pull of vertices that are near other joints (it expands its weight of the pull)

Drop off rate - leave it

Everything else is Ok

Bind Skin (it turns purple)

In Outliner - choose Show - Objects - Clear Below

Select the mesh and look at Channel Box - should see skinCluster1
will show multiple skinClusters if they bind more than one thing
tweak1 will be there too

Select any joint except the ends - will have bindPose1 in the Channel Box
Painting the Weights
Show the Nurbs Curves again

Grab mid torso nurbs ctrl and rotate the sack to show a kink in the waist

Select the surface and under Skin menu - Edit Smooth Skin - Paint Skin Weights Tool Options

**It will show the influenced area with white if you are in 5 (smooth shading)
White is 100&perc; effect the joint has on the skin and grey is 50% and black is 0% or no influence

Hold B and drag in the perspective window to change the radius
Opacity leave at 1 or change it to less if needed
open Stylus Pressure
make sure stylus Pressure is checked and select Pressure Mapping : Opacity

Use a tablet to paint the weights

Influence - select each joint by highlighting it from the list
Hit the 3 to see it as smoothed then switch to 1 to see normal - this is only for viewing
4 is the wireframe view
As you select a joint in the Influence outliner, you see it in the modeling window

In Paint Weight Options, Paint Weights -
Replace puts new values over the original
Add will add it to the existing
Scale will scale it by the value
Smooth will smudge values together

ONLY use Add and keep changing between the different joints and adding more weight where needed

Can change the Value: 0.2 or to some other number to effect the amount of pull

Paint the vertices only - look at the line not the shades of grey
Use the Control mouse move to rotate the view
Keep zooming in and moving the view to see what you are working on
Get the line or crease smooth so the deformation looks right
Just paint one side if the geometry is symmetrical - we can mirror it later

If you accidently add too much, select the nearest joint to the mistake area and then add the mistake area back to the joint it should be added to

Set the rotation back to 0 to get it back to original stance when you are done with that one

Go to the next nurb circle CTRL and then rotate to see it kinked
Smooth it (3) then go back to 1 to see what it will look like when you will smooth it later

Paint roughly to start and then you can go back and paint it better when you animate it.

To mirror the painted weights:
Character needs to be at the original bind pose (set all CTRLs to 0)

Select a joint that has had its weights painted, and Skin menu - Go to Bind Pose
(in the feedback line, it says gotoPinePose; (no error)

Then select the surface
Skin - Edit Smooth Skin - Mirror Skin Weights Options

Mirror across: YZ
Direction: Positive to Negative if they paint the positive side
(look at the arrow to see what side you painted)


You can Select surface then go back to Skin - Edit Smooth Skin - Paint Skin Weights Tool - Options to see that they are symmetrical

You cannot change things after skinning:
add joints
  • modify hierarchy
  • modify surface
  • add geometry
  • add controllers
  • To animate:
    Go to Windows menu - Settings/Preferences - Preferences

    Settings - NTSC (30 fps)
    Animation - YES Weighted Tangents
         Tangents: Default in taqngent = Linear
         Tangents: Default out tangent = Clamped

    Timeline: Playback speed: Real-time [30 fps]

    Go to the first frame and pose your sack using the CONTROL curves (only)
    DO NOT rotate the joints or anything other than the control curves
    Set Keys for each curve you changed

    Go to another frame and pose the character again
    Set the keys on the control curves

    You are working POSE to POSE
    Don't worry about the pinched skin nor the fluid movement of the character.

    When you have a section done with the poses set, you can go into your graph editor and select all the keyframes for a few poses and change the tangents to spline.

    You will then have to go into the graph editor and manipulate the curves to get the correct timing.

    You will need to go back and paint weights to fix the kinks later.

    Use the Principles of Animation to help you work out your timing, anticipation and other important aspects of animation that will make your piece good.

    Work on one section and then playblast it. Take the playblast and put it into your animatic.

    Go back and fix that section and then render it out and put that in the Animatic.
    Then work on another section (repeat until done)