SKINNING CGDD 4113 WHAT IS SKINNING The process

SKINNING CGDD 4113

WHAT IS SKINNING? • The process of binding a skeleton to a mesh • Methods: • Parent binding • Requires models to be separate • Individual mesh is “parented” to individual bone • Rigid binding • Vertices closer to a bone will follow that bone • Lattice binding • Create a lattice deformer, rigid bind the lattice to the bones • Smooth binding • A vertex or CV can be influenced by multiple bones

PARENTING • Each cylinder to each bone • Test via rotations

RIGID BINDING • Two skeletons, one NURB and one poly – each subdivided 10 • Skin->Bind Skin->Rigid Bind

EFFECTS OF BENDING • Polys are made of vertices • NURBS are defined by CVs

MEMBERSHIP • Edit Deformers->Edit Membership Tool

FLEXORS • Type of deformer to prevent cracking • Useful for polygons Without Flexor With Flexor

SET DRIVEN KEYS • Can set keys for the flexor in various positions • Animate->Set Driven Key->Set • The middle joint’s Y rotation will “drive” the points of the flexor lattice Note: When the book says “Zero the rotation”, just clear them in the channel bo

LATTICE BINDING • Create a lattice deformer for the polygon • Rigid bind the root joint to the lattice • Finish by changing the ffd 1 node (local influences) to 4 • Gives a much smoother appearance • Easier to edit membership! Lattice CVs vs. vertices • Can also use Driven Keys to define a bulge for the bicep

SMOOTH BINDING • Skin->Bind Skin->Smooth Bind • Sweet == true

WEIGHT PAINTING • Not covered in this book • Something good to look into • “Paint” how much a bone will influence vertices

GETTING BACK TO OUR CHARACTER… • Start by setting the preferred angle (RMB on the pelvis joint) • Select only joints that should affect the mesh • Best done in the Outliner view • Use Smooth Binding! • Wireframe turns purple • Smooth bind the eyeballs

RIGID BINDING • Eyes (to eye joints), eyelids (to head joint) and collar (to neck)

WEIGHT PAINTING • Try bending the shoulder… • Experiment with weight painting! Pr s m oble

JOINT DEGREES OF FREEDOM AND LIMITS • A way of restricting how the joint moves • Found in the Attribute editor