SCA 15: Eurographics/SIGGRAPH Symposium on Computer Animation
Permanent URI for this collection
Browse
Browsing SCA 15: Eurographics/SIGGRAPH Symposium on Computer Animation by Subject "based animation"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Animating Articulated Characters using Wiggly Splines(ACM Siggraph, 2015) Schulz, Christian; Tycowicz, Christoph von; Seidel, Hans-Peter; Hildebrandt, Klaus; Florence Bertails-Descoubes and Stelian Coros and Shinjiro SuedaWe propose a new framework for spacetime optimization that can generate artistic motion with a long planning horizon for complex virtual characters. The scheme can be used for generating general types of motion and neither requires motion capture data nor an initial motion that satisfies the constraints. Our modeling of the spacetime optimization combines linearized dynamics and a novel warping scheme for articulated characters. We show that the optimal motions can be described using a combination of vibration modes, wiggly splines, and our warping scheme. This enables us to restrict the optimization to low-dimensional spaces of explicitly parametrized motions. Thereby the computation of an optimal motion is reduced to a low-dimensional non-linear least squares problem, which can be solved with standard solvers. We show examples of motions created by specifying only a few constraints for positions and velocities.Item Hands On: Interactive Animation of Precision Manipulation and Contact(ACM Siggraph, 2015) Humberston, Ben; Pai, Dinesh K.; Florence Bertails-Descoubes and Stelian Coros and Shinjiro SuedaHumans show effortless dexterity while manipulating objects using their own hands. However, specifying the motion of a virtual character's hand or of a robotic manipulator remains a difficult task that requires animation expertise or extensive periods of offline motion capture. We present Hands On: a real-time, adaptive animation interface, driven by compliant contact and force information, for animating contact and precision manipulations of virtual objects. Using our interface, an animator controls an abstract grasper trajectory while the full hand pose is automatically shaped by proactive adaptation and compliant scene interactions. Haptic force feedback enables intuitive control by mapping interaction forces from the full animated hand back to the reduced animator feedback space, invoking the same human sensorimotor processes utilized in natural precision manipulations. We provide an approach for online, adaptive shaping of the animated manipulator based on prior interactions, resulting in more functional and appealing motions. The importance of haptic feedback for authoring virtual object manipulations is verified in a user study with nonexpert participants that examines contact force trajectories while using our interface. Comparing the quality of motions produced with and without force rendering, haptic feedback is shown to be critical for efficiently communicating contact forces and dynamic events to the user.