Péter Borosán Rutgers University Doug DeCarlo Rutgers University Andrew Nealan Rutgers University...
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Péter Borosán Rutgers University Doug DeCarlo Rutgers University Andrew Nealan Rutgers University Yotam Gingold George Mason Ming Jin Rutgers Universi ty RigMesh: Automatic Rigging for Part-Based Shape Modeling and Deformation
Péter Borosán Rutgers University Doug DeCarlo Rutgers University Andrew Nealan Rutgers University Yotam Gingold George Mason University Ming Jin Rutgers
Pter Borosn Rutgers University Doug DeCarlo Rutgers University
Andrew Nealan Rutgers University Yotam Gingold George Mason
University Ming Jin Rutgers University RigMesh: Automatic Rigging
for Part- Based Shape Modeling and Deformation
Slide 3
This Game Is Rigged! Sketch-based tools like Teddy (1999) have
been around for many years. While these tools make modeling much
easier, they do nothing to facilitate rigging, establishing the
underlying skeleton of joints (nodes) and bones (edges). Skinning,
the association of the visual representation of the characters
surface with the joints, is also a labor-intensive task.
Slide 4
Rigging The System This research unites modeling, rigging, and
skinning into a single tool, allowing the user to interactively
re-model, re-rig, and re-skin at any point in the process.
Slide 5
Decomposing The Silhouette From a users 2D sketch, the system
generates axes that will be used to determine the 3D skeleton and
surfaces. First, the user draws the 2D silhouette of the shape.
Second, a Chordal Axis Transform is used to find the midpoints of
chords of tangency for circumscribed disks within the shape. Third,
the midpoints are smoothed into axes, with (green) junction
triangles exploiting symmetries where three axes converge and
(yellow) rectangular regions connecting some junction triangles.
Finally, the junction triangles and connecting rectangles are
merged into connecting regions; everything else is considered
cylindrical.
Slide 6
Generating The Surface The 3D grid is generated from the
decomposed 2D silhouette. Generalized cylinders are easily
generated from the 2D cylindrical regions. Neighboring generalized
cylinders are connected with triangle strips. The boundary vertices
of the triangle strips are then used to generate a primitive grid
across the connecting regions. A least- squares method is applied
to smooth the entire grid.
Slide 7
Generating The Skeleton The connecting regions and cylindrical
regions are used to determine the skeletal structure. Trapezoids
are fit to the cylindrical regions, with a bone corresponding to
the central axis of each trapezoid. A joint is added to the center
of each joint triangle, and a bone emanates from that joint through
the center of each side. Short bones inside connecting regions are
collapsed in order to eliminate redundant degrees of freedom for
controlling the shape. Skin weights are calculated to determine the
extent to which vertices on the 3D surface are affected by the
various bones.
Slide 8
Interactive Merging Three means of merging 3D models are
provided. Snapping Join two skeletons by making their two joints
coincide. Splitting Insert a joint in the middle of one skeletons
bone in order to create a bone between it and another skeletons
joint. Connecting Create a new bone joining the joints of two
separate skeletons.